Tuesday, December 20, 2011

How far is 50 feet?

Converting from feet to meters is a subtle problem in writing scientific articles for lay audiences in the United States, and is likely to remain so for the foreseeable future. Using Google, I picked four popular web sites to ask for a conversion factor.  All four agreed that:

     50 feet = 15.24 meters.

So that's the number we should use, right?

Wrong! At least in most cases, when we write "50 feet", we don't mean 50.00 feet.

We may mean 50 + 1 feet, 50 + 5 feet, 50 + 10 feet, or even 50 + 25 feet. Each "translates" differently.

50 feet converts to 15.24 meters, 51 feet to 15.5448 meters (using  http://www.onlineconversion.com/length_common.htm), and 49 feet to 14.9352 meters; so 50 + 1 feet should be converted to 15.2 + 0.3 meters. (The extra two or three digits do not provide more accuracy here).

Similarly, 55 feet converts to 16.764 meters, and 45 feet to 13.716 meters; so 50 + 5 feet should be converted to 15 + 2 meters. 60 feet converts to 18.288 meters, and 40 feet to 12.192 meters; so 50 + 10 feet should be converted to 15 + 3 meters. Notice that the "translated" uncertainty for 10 feet is not the double of what it was for 5 feet!

Finally, the error for 50 + 25 feet is calculated as follows: 50 feet converts to 15.24 meters; 75 feet to 22.86 meters, and 25 feet to 7.62 meters; leading to a conversion of 50 + 25 feet to 15 + 8 meters.

If errors are not assigned, you are better off "translating" 50 feet as "about 15 meters."

A professor of mine used to say that a number is not complete without its uncertainty assessment. Another unrecollected source distinguished between "naked numbers" -- without uncertainty values -- and "clothed numbers" -- those with uncertainty listed. Try not to let your numbers freeze this winter.

Thursday, September 29, 2011

A little problem in Martin Cruz Smith's "Rose"

Now that the long series on avoidable evils and mineral collections is finally complete, I plan a few blog entries on miscellaneous subjects.
      One of the unsung highlights of Tucson in February is the Friends of Pima County annual book sale. There are 100s of thousands of books; some in any category you can think of, although few are technical. I've acquired some unsuspected gems at very low cost, and there are always plenty of novels at $1 each (hardcover) for your airport and summer reading.
     One such summer book was the novel Rose, by Martin Cruz Smith (1996). Smith is mainly known for his Arkady Renko mysteries, but has also written a book on Los Alamos in the early atomic era (Stallion Gate), and some other books I have not read. Most of the ones I have read feature a competent protagonist and an air of hangdog inevitability; no wisecracking supermen here.
     For us geologists, the protagonist of Rose is Jonathan Blair, a mining engineer newly returned to Victorian England from Africa; and the locality is a coal-mining town (and the mine itself). The mystery is resolved underground, and therein lies the rub...
     I have been in old mines (such as the Bell iron mine in Newfoundland) where the ore is moved underground by horse-drawn minecarts. As is logical, the mine tunnels on any level slope down to the mine elevator, so that the "pit-ponies" only have to haul empty carts uphill, and haul loaded carts downhill. For some reason, the tunnels in the Hannay coal mine slope the opposite way: down to the coal workings and up to the elevator. If anyone knows whether this is typical for a coal mine, or just the invention of the author for plot reasons, I'd like to know.

Monday, September 19, 2011

The evils that beset mineral collections: 16. Poverty, death and the disposition of goods and records

Let's talk about death first.

You may leave behind you:
  • Grieving parents,
  • Grieving children,
  • Grieving creditors,
  • Warring relatives,
  • Two or more people who think they inherit the same item, or
  • A spouse who has no idea what you had, or what it is worth.
But what do you want to leave behind you?
     Do you want your collection to be an intact entity? A source of revenue for your heirs? Do you want the items in it to retain their provenance information, and a record of their presence in your collection? All these lead to estate planning considerations.
     If you want someone or some institution to inherit and keep your collection intact, it is best to negotiate this while you are still alive. In the case of  institutions, it is extremely helpful to provide an endowment to support the collection (this is true even if you are gifting a few items, with no requirement to keep them together, and no strings attached). In the case of individuals, give some thought to what might happen as their circumstances change; it will not be possible to guarantee your desired result in perpetuity.
     If your want your heirs to get the most value out of your collection, consider evaluating some mineral dealers or an auction house while you are alive. (As you get older, you might want at least one of the dealers to be substantially younger than you.) Check with your tax lawyer; it might be more appropriate to sell the collection yourself and provide monetary gifts than to leave disposition for your heirs to handle.
     If you want a specific heir to get a specific item, make sure your intentions are clear and in writing. You might also make sure that this heir wants this item, especially if it has specific upkeep requirements (see the rest of this series).
     If you are willing to split up the collection, it again may make better sense for you to dispose of it than for you to leave it for heirs to deal with.

In all cases, however, you will need to provide three important types of information in your estate plans.
1) Where are all the mineral specimens? Are any in a safe deposit box? Are any on loan, or on exhibit elsewhere? Be as specific as possible and update this information whenever there is a change.
     1a) And while we are at it, do you have any specimens in your possession that don't belong to you? (E.g., borrowed, on memo or on consignment and not yet paid for, etc.) Those should be specified, as well as any with shared ownership, etc.
2) Where are the collection records stored? Is there an obvious link between each specimen and its related information? If you have information stored as computer files, are they password protected? If so, the current password needs to be provided.
3) Who knows this information -- where the specimens and records are, and how to access them?

Poverty is a difficult issue. You may have to sell your collection, or less likely, get a loan using it as collateral. Make sure you know what comparable specimens are selling for, but do not expect to get any amount close to the fair market value for your items, unless you are prepared to spend a lot of time (and some money) marketing them. (25% of FMV -- for your most sellable specimens -- may be closer to the truth.)
     Remember, if you are hurting for money, other people are probably in the same situation. So liquidity -- the ease with which you can convert your specimens into money -- is likely to be a problem as well.

Monday, August 29, 2011

The evils that beset mineral collections: 15. Inclination, boredom, lack of discipline, and new worlds to conquer

You may notice that this column does not appear every week. Its sometimes sporadic occurrence reflects today's set of evils: inclination, boredom, lack of discipline, and new worlds to conquer.  Let's add perfectionism to the list as well.

If you have a small and well-organized collection, these evils are not so much of a problem. But suppose, like me, you last cataloged a specimen (as opposed to adding it to a running list) in the 1990s. In the mean time, I have changed cities, changed jobs, taken several vacations, and yes, continued to collect minerals, rocks, and a few gemstones [including synthetics and imitations]. I have acquired some nice equipment for the visual examination of minerals: a gemological microscope, a viewing box, etc. But I have not set up an environment to label specimens; worse, I have not unpacked my existing collection after the move a dozen years ago.

Well, the new space isn't ready yet: it leaks sunshine (see Evil #7). When I had the money to prepare it, I didn't have time; and now that I have more time, money is tighter. The first steps to preparing the space are big ones. So blame inclination, the lack of funds, and a lack of discipline (and the Internet, that large vacuum-er of time).

Certain aspects of collecting are more pleasant than others. It's great fun to go to Tucson; it's fun to build displays; it's not as much fun to make handwritten labels in triplicate, or to find a LaTeX compiler, or ... This is an aspect in which perfectionism can slow you into immobility.

And if you formed your collection when you were much younger -- or, worse, inherited it -- by the time a piece is cataloged you may not remember why you got it. So if you must procrastinate, keep notes (with the specimen, and away from sunshine, insects, rubber bands, etc.).

What if your interests have changed? If now to minerals you prefer to collect mineral books, or make fishing flies, or raise a family? It may be appropriate to set your annotated collection aside until you find (or raise) an enthusiastic apprentice who can grow into it. Or find a deserving museum; or a mineral dealer or  auction house if the money would come in handy.

Or persevere: sometimes the solution is to break the big steps into little steps. If you can't even handle a little step, make it easier to do it next time, by clearing off a space, or collecting supplies, or tackling whichever obstacle is blocking your progress.

Museums have the notion of stewardship: that one has a responsibility to that which has been judiciously acquired. Be the best steward that you reasonably can be.

Monday, July 11, 2011

The evils that beset mineral collections: 14a. Fasteners and computer programs

I forgot to mention another important class of non-archival materials that can damage the support information for mineral specimens: rubber bands, staples, paperclips and other fasteners. It is possible to get plastic and plastic-coated paperclips, and stainless steel staples are sometimes available. If you need a replacement for rubber or elasticized bands, however, your best bet is to use archival string or ribbon.

The biggest boon to collections in recent years is the availability of computer software for managing information.

It is important to back up software early and often.  It is also important to have off-site backup on a regular basis, and to have a backup copy of your information in your control in case of electronic catastrophes (like the Internet becoming unavailable).

What form of back-up is appropriate?  Over the years, I have stored information on paper tapes, punched cards, magnetic tape, 8-inch floppy disks, 5" floppy disks, 3.5" not-so-floppy disks, CDs of various kinds, and flash drives. Each of these media have expiration dates, due to medium degradation and/or hardware obsolescence. So as technology changes, your backup copies have to be copied or translated onto new media. This may not be a lossless process.

Similarly, the software available for documentation of your collection can change over time.  These days, I keep most of my data in Excel databases; but I can remember when Microsoft Works was a better platform for graphics. In the 1970s, much scientific programming was done in Fortran, and I can remember running into problems updating a program written using unsupported features from an earlier Fortran version. Many cataloging programs today are proprietary; what happens to your catalog if the company producing your program goes out of business? Can you still get support for your software?

Finally, if you use password-protected programs to document your collection, make sure you still know the password as long as you need your backup. Heirs and executors may need your password as well.

Monday, July 4, 2011

The evils that beset mineral collections: 14. Newspaper, tape, glue, and other nonarchival materials

Let's talk about the materials that surround your minerals. These include: boxes, labels, packing material, repair materials, and documentation. All of these could decay over time, possibly damaging the specimens themselves, or losing their accompanying information.

Newspaper is a common wrapping material, used to protect specimens while collecting in the field, and while transporting from mineral shows to your home. It's tempting, in the field, just to write the collection details -- where, and what date -- on the paper  itself. The problem with this non-archival material is that it decomposes over time; paper made from wood pulp turns brown in sunlight and gives off acidic fumes. Eventually, the paper flakes into small particles. Some newspapers also have ink that can rub off on specimens, discoloring them. And the acid from the paper can react with some minerals.
     Other materials used to wrap specimens in the field include butcher's paper (or shipping paper, toilet paper, paper towels, tissue paper...), dry-cleaning bags, canvas bags (used by many field geologists), beer flats, and film canisters. Almost all inexpensive paper is pulp paper, and will break down forming acid over time.
Cardboard boxes are frequently used to store individual specimens; beer flats for transport are also cardboard. In my experience, cardboard is more durable than paper with regard to exposure to sunlight and heat, but it is not a permanent material, and is again wood-pulp based. Archival cardboard boxes are available. Sometimes plastic trays are used, but not all plastics are archival, so check the material before you decide to use it.
     Fragile specimens are sometimes kept in boxes padded with cotton or polyester fibers. Cotton is not archival and subject to insect damage, and any fibrous material can get caught up in specimens with points or cavities. An least one museum of my acquaintance pads specimen boxes with an archival closed-cell foam material such as "Volara."
      Many collectors use wood cabinets. Some woods, like oak, give off fumes over time, so are not archival for containers. (The British Museum used to recommend mahogany.) Also, some finishes give off volatiles.

What about labels? The paper may be pulp-based, so non-archival; the ink may be unstable to sunlight, and fade away; the label may have been previously torn and repaired with cellophane tape. Cellophane becomes yellow and stiff and loses its stickiness over time. (Other tape kinds can be even worse, like old duct tape, which leaves gooey residues.) Some collectors save old labels in mylar or other archival envelopes, because they are valuable to the provenance of the specimen, no matter what they are made of. But for your new labels, try to use archival materials.

Older specimens sometimes were repaired with non-archival glues, or coated with yellowing shellacs. Modern epoxies and UV-setting resins may be more permanent. Another repair technique is to use an adhesive that is easily soluble in something the specimen is not (e.g., casein glues for non-water-soluble specimens), so that the repair is not permanent and can be redone if there is a later need to do so.

Finally, on the subject of preservation of documentation, we need to discuss computer files. This will be a separate blog entry.

Monday, June 27, 2011

The evils that beset mineral collections: 13. Sulfur, Pyrite, and Other Minerals

Minerals that damage other minerals?  Read on, oh Viewer...

A standard way to display minerals is in Dana Order: by anion group starting with native elements, sulfides and sulfosalts, and simple oxides; and ending with framework silicates. A major problem with this display procedure is that it puts elemental sulfur and elemental silver in proximity.  (Note that alphabetical display order also has this problem, though.)

What's so bad about that? Sulfur has a high vapor pressure, meaning that sulfur releases gas at room temperature and pressure. (It has a pronounced smell.)  In a small enclosed place, concentrated sulfur vapors react with metallic elements and sulfides, such as native silver and native copper, to create surface tarnish layers. This makes the tarnished minerals less attractive and can lead to their decomposition.

Pyrite and marcasite have a different problem.  These minerals decompose in humid conditions, producing sulfuric acid. A microbe is thought to be involved. Some museums store these minerals isolated in evacuated plastic bags to prevent them reacting with their surroundings: dissolving labels, boxes, and so on. Another reason for isolation however is to prevent specimens from contaminating each other, if a microbe is involved.

Finally, some radioactive minerals are alpha emitters, and as such can create radiation damage in other minerals if left in very close proximity (touching) for long periods of time. This process often happens in nature (producing for instance smoky quartz), and could possibly happen in collections left alone for decades; however, I know of no examples of this.

Monday, June 20, 2011

The evils that beset mineral collections: 12. Loans, Trades, and Other Collectors

Surely your fellow collectors can be relied upon to leave your specimens undamaged and in your possession! Well, not always... There were rumors in my youth about an esteemed professor -- now long deceased -- being searched as he left a country, with the search revealing several important specimens from the country's national collection. And some people are accident-prone. Most of your fellow collectors are undoubtedly honorable people, but if you don't want to suspect your fellows, and wish to prevent mishaps, there are some things you can do to protect your collection.

When showing your collection to a group, only show it in closed cases. You can open a case to hold up (or pass around) a specific piece, but don't leave people with unsupervised access; they might knock something over.

If you are showing your collection to an esteemed guest, let him or her ramble with you at their elbow to explain, describe, and tell stories about your wonderful specimens.

Trades have two sets of hazards. You may get the worst part of the bargain, but that is an inevitable part of a collector's education. Learn from your mistakes.

The second hazard lies in the exchange circumstances. Pack any specimens to be mailed securely. Be prepared to deal with the circumstance that your trade partner's specimens may get damaged, and have an agreement in place as to how the two of you will deal with damages or mail losses. You may want to send things using a secure form of transportation, such as registered insured US Mail.

When you loan pieces, the loan is usually for a display or to a museum. A loan should have a clear description of who is responsible for transporting the piece, and a clear notion of the duration of the loan. Many museums have special loan paperwork. Also think about security and insurance for your loans. If something happens to the destination site -- a theft, a fire, etc. -- you should be able to demonstrate that the item in question belonged to you.

Sometimes items are sold or traded on approval; again, have an agreement in place in writing before you send out an item.

The purpose of written agreements is to make a trade, loan, or other deal run smoothly when unexpected events occur.

Monday, June 6, 2011

GIA Symposium Poster: for Gem Dealers who want to sell Mineral Specimens.

Last week I attended the 6th GIA Symposium, which was about research and business of gem materials. I mainly attended the research track, especially colored stone and pearl research. I also was able to attend the field trip to some Pala mines prior to the Symposium.

My poster, intended for gem dealers, explains what mineral collectors are looking for in a specimen. Some gem rough can be sold as mineral specimens, but the proper material must be recognized and marketed appropriately.

The images are from Rock Currier, and are copyrighted by him. These can also be found on the mindat.org website.

Email me at mlj@cox.net if you would like a copy of the PDF file.

Monday, May 9, 2011

The evils that beset mineral collections: 11. Children and Other People

Here I am distinguishing "children and other people" from fellow collectors. This blog entry is about mineral-naive people who may interact with your collection. (The classic apocryphal example is the maid who carefully dusts your millerite geode to get rid of those hairs in it.)

Some mineral specimens should not be touched; others should not be picked up. Etiquette for guests is to ask permission first, and to hold the specimen close above a soft surface (such as your free hand) while you examine it. Heavy minerals (including galena and gold nuggets) are easily dropped. Some crystal tips can cleave off, like apophyllite or even topaz.

Attractive specimens sometimes disappear when visitors are allowed free access to a collection. If you like to give samples to encourage children (which is a very good thing to do), do not let them confuse ones to which they are welcome with ones you would rather keep.

Mineral specimens can hurt people also. Okenite specimens are sometimes demonstrated as "pattable" furry minerals; but related species such as pectolite will leave slivers in one's fingers. (And other velvety mineral specimens, such as manganese oxides, are easily crushed by patting them.) It's wise to wash your hands after handling minerals, especially ones you don't know, or ones you do know to be poisonous.

A mineral collector should not expose naive or easily frightened guests to radioactive minerals, asbestos-habit amphiboles, or arsenic ores.

Monday, May 2, 2011

The evils that beset mineral collections: 10. Insects and Other Pests

Most mineral specimens are not edible, but things associated with them are: labels, glue, wool batting, etc. Boxes make cozy homes for rodents, who may add their own specimens of scat and crystalline urine. Humid conditions promote mold growth (see Evil #4); humid conditions with sunlight promote plant growth. An untended collection may become an ecosystem. 
  • Insects: The common pests depend on your region. Silverfish nibble on paper, termites eat cellulose-rich material, dermistids (carpet beetles) and moth larvae eat wool. Cockroaches like people food but spread grease where they go.
  • Rodents are more likely to be disruptive than to eat minerals or labels. They can nest in storage boxes, re-arranging their contents. Rats leave grease tracks and pee as they travel. Sometimes rodents bring their own collections into their homes; you may find stashes of food interspersed with your minerals.
  • Birds can nest in rafters over your storage area and leave droppings; they can also carry fleas and ticks.
  • Medium-sized mammals investigating a garage or basement collection include raccoons, skunks, feral cats, etc.Watch out for scratching posts, bad odors, nursery sites, bathroom sites, and rabid behavior. (Not that your minerals will catch rabies, grow fangs, and start foaming at the mouth; but your curator might!)
  • Plants are usually benign, but can grow roots or tendrils into a space where they are not welcome. Your collection does not need a burst sewer pipe in its vicinity. I have a wisteria that attempts to become a house planet every summer, prying open windows and growing meter-long indoor tendrils. Plants (trees) can also fall over onto collection spaces. 

Tuesday, April 19, 2011

The evils that beset mineral collections: 9. Moving

Moving a collection does not have to be a disaster. Ideally, you should have the destination already prepared, with enough space for your collection; everything is well-organized, and the move goes smoothly. In real life, however, many obstacles can arise.

1. Scheduling: A scientist friend once told me to expect everything to take three times as long as you expect. The need to move a collection is often due to outside forces: a reorganized academic department, a new home, etc. One very common reason is the sale or donation of the collection; work with the former owner (or estate) to make sure you have the time you need. If you are shipping specimens from one place to another, make sure there is an appropriate place for the containers at the receiving end.

2. Help, and the lack thereof: A quote often seen in fiction goes, "Friends will help you move; good friends will help you move bodies." You are likelier to need help packing than transporting. Such help should be experienced with minerals (or else you should keep the delicate specimens away from most assistants), enthusiastic, and above all trustworthy. They should be able to follow your orders rather than deciding to improve those orders without telling you. You may need friends or volunteers to help if you have a tight schedule; on a very tight schedule you may have to rely on paid professional movers.

3. Packing: Two considerations are the distance the collection must travel and the elapsed time that it will stay packed. When I moved about 80 boxes of specimens from Massachusetts to California in the 1980s, I shipped some through the mail in cardboard boxes, some in wooden crates (and cardboard boxes) that went in a moving van, and one flat of delicate this-end-up mineral specimens stayed in our car as we drove across the country. I packed individual specimens with their labels in paper (especially toilet paper), plastic dry-cleaning bags, and sometimes cotton box liners; better materials are probably available now. Field collected specimens were often wrapped in newsprint. The collection stayed in their boxes for about a year before unpacking.

4. The dropsies: The rule of thumb I heard years ago about packing boxes was that you should plan for the contents of your package to survive a fall from a six-foot height onto concrete. If you have visited a post office at Christmas-time, imagine those other boxes being dropped onto yours. A specimen unable to survive such treatment should be shipped another way. There are stick-on detectors that measure the amount of force that your package has been subjected to.
     A famous mesolite specimen of my acquaintance was supposedly shipped from India while sewn into a wooden box and packed in soap flakes; it had its own first-class airline seat. Which brings us to...

5. Transportation: How will your collection move? Is your carrier secure against theft and damage? Is your collection safe at the temperatures (and possibly pressures) it is likely to be exposed to? Will it be detoured or derailed by hurricanes, snowstorms, or floods? You may wish to divide the collection into separate units to be transported in different ways.

6. The destination: Is the destination ready to receive your collection?  Sometimes this is not possible, as when an old museum is renovated. In that case, where will the collection be stored until its destination is ready? What are its conditions like, in terms of environmental control and security?
     How will your collection be delivered? Is access adequate? Is there a risk of items disappearing from the loading dock, or of dropsies as boxes are carried upstairs?

7. Unpacking: should be done with at least as much care as packing. Have a plan and a place set aside for dealing with broken specimens. Listen for crunching sounds and feel for unexpected softness as you unpack.

    Tuesday, April 12, 2011

    The evils that beset mineral collections: 8. Large-Scale Disasters

    In light of recent events in Japan, this entry may be timely. The original title (back in August 2010) was "natural disasters," but human-caused events such as nuclear meltdowns should also be considered.

    So which disasters are relatively likely?
    • Fires
    • Floods, including tsunamis and hurricanes
    • Wind damage, including tornadoes
    • Earthquakes
    • Building settling and collapse
    • War
    • Volcanoes, nuclear power disasters, and other things requiring rapid mass evacuation
    • World-destructive scenarios: asteroids, all-out nuclear war, etc.
    First, your collection is not the most important thing in case of emergencies. Take care of yourself, your family and your pets before you worry about your collection.

    Second, prepare in advance for likely hazards. Consider collection insurance. Have off-site backup of your collection information. Consider storing your least replaceable/most valuable specimens in a fire safe or off-site safe deposit box. Take pictures of your most important pieces and store these off-site.

    The likeliest disaster anywhere in the country is a fire. Mineral specimens are more susceptible to fire damage than one might think. Many will melt or shatter. Labels and associated information can be destroyed. Smoke damage may take a competent professional to remove. Consider fire-proof cabinets for your most important specimens. Have a plan for local (in-home) fires, and follow your city, county and state guidelines for regional fires. (If you live in a fire-prone area, you may want to pack some of your favorites in a bag to go.) Fire extinguishers and water can also damage specimens, so consider extinguisher types if you have an extensive collection. A final thought is that specimens-plus-fire can pose a hazard to firefighters, especially if they decompose to create poisonous fumes.

    Floods occur along seacoasts, along riversides, and inside buildings with sprinkler systems. Water damage causes specimen dissolution, label disintegration, and mold hazards. Often agitation and unplanned movement accompanies water damage, so labels may be separated from their specimens, or even reduced to unreadable pulp. Labels and soluble specimens can be protected by keeping them in sealed waterproof envelopes and containers. Regional flooding may cause everything to be swept away, so consider solid rust-proof cabinets.

    Wind, earthquakes, and building collapse are all primarily movement problems. Storage and display cases should be chosen with these factors in mind. Heavy cabinetry helps against windstorms, although roofs and nearby trees are more important factors in overall safety. In earthquakes, however, the ground moves out from under you; so unsecured heavy cabinets become "loose cannons." And don't make your cabinets too heavy for your floors! Additional considerations are drawer slides that "catch"; safety glass for display cases; raised shelf edges in earthquake country; and museum wax to secure specimens.

    In a war, volcano eruption, or other event when you may have to evacuate for an indefinite period, there is no guarantee your collection will survive if you leave it behind. Consider an evacuation plan for your collection in advance if your circumstances warrant it, and the collection is that important to you.

    If the world ends, your collection is on its own.

    Monday, April 4, 2011

    The evils that beset mineral collections 7: The Sun

    What's so bad about the Sun? Two things: light and heat.

    Light fades labels, which is its commonest problem. However, some minerals are themselves light sensitive, such as the ruby silvers proustite and pyrargyrite. In the presence of light, these deep red sulfosalts react with air to form silver surface layers, which in turn oxidize to black silver oxide. Proustites kept in the dark, even after many years, can be as red and lustrous as the finest cinnabars.

    Some sunlight effects are due to its ultraviolet component, so UV-blocking film may be helpful if you want to show your collection in a sunny room. However, UV-blocking film can also shift an object's apparent color; and items can possibly fade in visible light. In general, to preserve collections and labels, use the least illumination necessary, and keep collection display rooms dark when they are not in use.

    As anyone who has a car with a black interior knows, the Sun's warmth can be concentrated to an unpleasant level. Some minerals are especially susceptible to quick warming, including sulfur and sphalerite. (In the case of sulfur, even the warmth from holding a crystal in your hand may be enough to crack it.) Keep these out of direct sunlight.

    Thursday, March 31, 2011

    Miscellaneous: Skunk with garlic

    Smells have an umbra and a penumbra. (These terms are taken from astronomy and mean "shadow" and "almost shadow", respectively.)
    When you are reasonably close to a source of strong odor (that is, in its penumbra), it has a distinctive smell: like incense, cat-litter boxes, or, in particular instance, skunks.
    However, when you are really close, in the umbra, the odor takes on many nuances, and can change entirely. One can detect the match flare in the incense, the catfood post-processing, etc. In the case of our recent nocturnal visitor, the skunk:
    --strong skunky mercaptans
    --raw sulfur
    --strong green onions (you know the ones that are really too big, but you eat them anyway?)
    --and really really strong raw garlic.
    Under our bedroom, two nights ago.

    I got to sleep by mentally completing the recipe: the skunk needed basil and oregano, tomato sauce, and to roast those garlic slices in olive oil until slightly brown before adding to the sauce.

    (Last night she was less panicky, so less stinky.)

    Monday, March 28, 2011

    The evils that beset mineral collections: 6. Dust

    Is dust evil? It seems omnipresent; but dust can create serious problems for your mineral collection in two ways: by its accumulation and by its removal.

    The contents of dust varies with environment. Dust in the outdoors or a garage is rich in finely powdered rock flour, as well as pollen and regional pollutants (diesel exhaust, etc.). Indoor dust also contains fine fibers, and may contain tars from smoking. Vaporized oils from cooking, spider webs, and many other things end up as dust.
    • Exhaust material and oils smudge surfaces, leave stains and may be hard to remove.
    • The quartz in rock flour scratches soft mineral surfaces and soft polished gems.
    • Fibers are hard to dislodge from delicate specimens, and are glaringly obvious in microscopy and micro-photography.
    • Thick coats of dust obscure labels and disguise features.
    Mineral specimens themselves can give off dust; some species occur as fine powders, and some specimens are friable. The powders could be radioactive, or asbestiform. Protection of a mineral collection also entails protecting collectors and visitors from the collection, so it is important to store powdery, liquid, and radioactive minerals in appropriate closed containers.

    Although dust can be bad, removing dust can also damage specimens and their labels. Use great care when cleaning either of these.

    Monday, March 21, 2011

    The evils that beset mineral collections: 5. Vibration and flexure

    Vibrations are waves of movement of the environment around a mineral. These include sound and shaking (from footsteps to earthquakes).
    Flexure, or flexing, is bending. Take a pliable material, like a paperclip, and bend it back and forth. Eventually it undergoes metal fatigue and snaps.
    • Delicate mineral specimens can fall apart due to repeated exposure to slight vibrations; know which of yours are susceptible to this, and keep them isolated from shocks. (Look for inexplicable dust around the specimen when it is on display as an indication it is susceptible to vibration damage.)
    • All powdery specimens are susceptible to vibrational damage; keep in closed containers.

    • The vast majority of mineral specimens will be damaged if the case they are in is overturned by an earthquake or comparable large shock. If you live in an area where earthquakes are a concern, consider storing your minerals in individual boxes lined with an archival foam material, like Volara.
    • A heavy cabinet or safe by itself will not protect your specimens from earthquake damage, unless it is securely anchored to bedrock or deep foundations. (Without appropriate securing, the cabinet can become a large heavy projectile.)
    • Raised edges on open shelving, "museum wax," Velcro, and other stabilizing materials can limit the movement of individual items in small or moderate earthquakes.
    • Many websites deal with preparing for earthquakes. In general, large heavy items should be kept on low shelves, and certainly not over one's head.
    Flexing and bending can damage metals and elongated crystals.
    • Thin mica sheets can withstand some flexing.
    • Silver, copper, and gold occur as wires and sheets that are sometimes bent into more aesthetic shapes. [This is debatably a treatment that should be disclosed.] Over-bending a specimen can cause it to break.
    • Some fibers are more elastic than others. Most fibrous specimens will be damaged by "patting" them; such as the black velvet surface of some psilomelanes. Others, like pectolite, can damage the person patting them! Okenite balls are sometimes shown to children as minerals one can pet, but the fibers are much less durable than plush animals.
    • Itacolumnite, or flexible sandstone, can lose sand grains when flexed.
    • Fibrous minerals can also be damaged by being dusted. (Millerite geodes are a common example of this.) Do not let inexperienced people dust, hold, or even touch your mineral specimens without supervision.

    Monday, March 14, 2011

    4a. The evils that beset mineral collections: Variations in humidity

    Often--but not always--correlated with changes in temperature are variations in humidity. These threaten mineral specimens by changing their solubility in air. I remember a salt crystal in the Harvard student mineral collection, then at the Science Center, that had developed a lovely set of salt rings surrounding it on the glass shelf in its display case. All the salt from the rings had originally come from the large crystal, and its faces were slightly frosted.

    Changes in humidity also threaten mineral labels and boxes for soluble minerals, just as dipping the labels or boxes in salt water would attack them.

    Possibly bacterial damage of specimens such as iron sulfides can be enhanced by humidity and its changes.

    Most museums try to keep their humidity constant, often at about 55% relative humidity. Sometimes you see humidity chart recorders in cases or rooms.