Tuesday, December 14, 2010

4. The Evils that beset mineral collections: Humidity

Some minerals are found in wet environments, and dry out.
Some minerals are found in dry environments, and pick up water.
Some minerals are water-soluble.
Some water-soluble minerals can dissolve and re-precipitate as the humidity in the air around them changes.
Some minerals react with the water in the air to form acid.
All these pose problems.
Let's look at some examples:
  • Hydrous borate minerals, such as kurnakovite, and hydrous carbonates like hanksite, grow in saturated brines. When removed from their brines, they develop white surface alteration. Some mineral specimens are coated with clear lacquer to prevent their surfaces from reacting; others are wrapped in plastic, or kept in closed plastic bags or glass jars. Lacquer coating should be noted on the records accompanying a mineral specimen, and disclosed if and when it changes owners.
  • Opals may dry out, leading to cracking or "crazing." Opals are mineraloids, not minerals, and have variable amounts of water, as well as varying degrees of structural organization. Many museums display opals with an open container of water in their cases, to prevent further drying out.
  • Some attractive uranium minerals, like autunite and zeunerite, are not stable in typical human-friendly environments, and naturally dehydrate (here, to meta-autunite and meta-zeunerite respectively). Most mineral collectors just accept this change as inevitable.
  • Many marcasites and some pyrites decompose in wet environments, producing sulfuric acid. This may be due to bacterial action. Some museums store these minerals in individual evacuated and sealed plastic bags to fight decomposition.

Monday, November 15, 2010

3a. The Evils that beset mineral collections: Temperature changes

In the last installment, I discussed temperature effects, but not temperature change effects.

The largest effect happens in situations where a collection is kept in places that can get below the freezing temperature of water. There is an effect called freeze-thaw disaggregation, which is seen in nature at rock outcrops: water seeps into the rocks and expands as it freezes, prying the rock apart. Minerals with fluid inclusions, or ones that are inadvertently wetted down (does your basement flood?) might suffer from such effects.

The other extreme is rare as an environment, but can occur to specimens with fluid inclusions when viewed through a microscope with hot lights, or while being photographed with hot lights. Some fluid inclusions contain gas bubbles (e.g., carbon dioxide bubbles), and these expand as a specimen is heated. In one anecdotal case, a gemstone exploded when held in someone's mouth.

Temperature cycling can also cause a mineral specimen to disaggregate. Each mineral has its own thermal expansion coefficient, which measures how much it expands as it gets hotter and contracts as it gets cooler. Anisotropic minerals (corundum is a good example) have different thermal expansion coefficients in different directions, and can even contract in some directions while being heated.
A matrix mineral specimen is an aggregation of different grains, often with varying orientation. The grains will typically push against each other as temperature climbs, and pull apart as temperature falls. This might lead to delicate specimens falling apart.

Tuesday, September 14, 2010

3. The Evils that beset mineral collections: Temperature and Temperature changes

Is global warming a threat to your mineral collection? Maybe.

First, let's talk mineral stability. Many mineral species are described that are not stable at room temperature, pressure, and humidity. However, most are stable in the environments in which they form (some are formed metastably, which won't be discussed more in this blog entry).

To form, minerals need a supply of nutrients (elements), and the appropriate pressure and temperature ranges. The conditions needed for mineral stability also include the relative amount of water available, relative acidity, and oxidation state. Minerals that contain other elements that may be in the gas or fluid phase, such as sulfur, selenium, and fluorine, may have additional requirements for stability.

Now look at minerals that are outside their stability range. Will these immediately decompose? Not necessarily. If the amount of energy needed to start the change or decomposition is high, the mineral may stay in the same state despite adverse conditions. This is called a metastable condition, and the best example is diamond.

However, many minerals do break down, and the conditions on earth that form minerals may not be represented in your collection. The most obvious low-temperature example is ice; another is antarcticite. Neither of these are stable at 20-25 C.

The opposite case is for high-temperature minerals whose crystal structures spontaneously distort at lower temperatures. Probably all so-called specimens of "beta quartz" are now alpha quartz, unless there is a mineral collection that keeps specimens above 550 C.

Wednesday, September 8, 2010

2. The evils that beset mineral collections: Space

Space, or lack of it, is often a problem for compulsive collectors like me. As zen comedian Steven Wright said, "You can't have everything. Where would you put it?"

Here are some typical space concerns:

Display space: How many of your minerals can be displayed at once? Would you like to display more, and if so, do you rotate the collection so that other specimens are sometimes on display?

What happens when you get new display pieces? Often, the existing display is rearranged to make space for the new specimens. Eventually, display clutter becomes a problem.

Can you see all the specimens on display from one position, or do you have to contort yourself to see what's on a lower shelf, or the items in the corners? If the latter, your display spaces may be too crowded.

Do no specimens touch? Is it clear which label belongs to each specimen? Is every label readable without moving any specimens? If so, you may have enough display space for the specimens you are showing.

Storage space:
Is it archival? Is it secure against rodents, insects, and other pests? Is it secure against theft, weather, and other hazards? These are all reasons that a garage may not be the best place to store some or all of your specimens. Weight and heat may preclude attic storage; water problems may preclude basement storage. You'll have to judge whether any of these will work for you.

For important specimens (or jewelry), you may wish to invest in a box in a bank vault. There are rumors of opals crazing in bank vaults due to lack of humidity, so think twice about storing opals there. You might also wish to save a copy of your mineral records in a remote site such as a bank vault.

Is it accessible? If you need to get access to a particular specimen in storage, it helps to know exactly where it is, and what you need to move to get access to it. It's easy to bury boxes under other boxes, so it's important that every box be labeled on all sides. "This end up" is another important message where needed.

Gemstone storage: For those of you with loose fashioned gemstones, how do you store them? Some people use individual pill-case type containers, some use small plastic bags, and some use stone papers. (Larger specimens or suites are often stored in their own lined cases or Riker Mounts.) Regardless of the storage method, gemstones should not touch each other; even diamonds get "paper wear" from other diamonds in the same stone paper.

Monday, August 30, 2010

1. The Evils that beset mineral collections: Time

How many ways can time damage a mineral collection?
The primary problem is in the retention of information, but minerals themselves can also be damaged.

How can information be lost?
  • If you haven't written something down, it can be forgotten. That includes the location of samples and information. Take the time to label your specimens, even if with temporary labels, as you acquire them.
  • Sometimes notes (especially receipts) are not prepared using archival materials. Paper crumbles, ink fades, tape becomes unsticky. Try to avoid using non-archival materials; make copies of unstable notes.
  • Computer programs become obsolete over time; computer media may not be stable (e.g., many CDs are only rated for 10 years), or their related hardware may become obsolete. (For instance, my Ph.D. thesis is on large-format magnetic tape, and prior to that I used punch cards to index collection information: these are now dead media.) If your information is archived on hard media, update the media regularly, and check that the information has not become corrupted in the meantime; if it is in "the cloud," still make your own backups.
  • When the time comes to pass your collection along to another place, will you be there to handle the transfer? Or will your heirs know where the specimens are, which have special care issues, which label belongs to each specimen, and who gets what? Collections deserve special attention in the estate planning process. (And does the recipient know the collection is coming? Give your heirs a chance to prepare for the collection's arrival.)
What can happen to minerals?
  • Over time, minerals can react with their environment. Sharp water soluble crystals can become rounded due to humidity changes over time; some pyrite and marcasite crumble due to bacterial contamination; acid paper reacts with sulfide minerals.
  • Metastable minerals can revert or decompose: for instance, hydrous (or "hydratable") minerals gain or lose water.
Some of these changes can be mitigated with a stable environment and isolation of some specimens; but some is inevitable.

Monday, August 16, 2010

The evils that beset mineral collections: Intro

This next series is on the evils to which mineral collections are heir: the things that make a collection less valuable, or less educational, than it might have been:
1. Time
2. Space
3. Temperature and temperature changes
4. Humidity and humidity changes
5. Vibration and flexure
6. Dust
7. The Sun
8. Natural disasters
9. Moving
10. Insects and other pests
11. Children and other people
12. Loans, trades, and other collectors
13. Sulfur, pyrite, and other minerals
14. Newspaper, tape, glue, and other nonarchival materials
15. Inclination, boredom, lack of discipline, and new worlds to conquer
16. Poverty, death and the disposition of goods and records

Some of these are necessary evils in having both a mineral collection and a life, but let's watch out for them.

Comments are welcome for any evils or other topics you'd like me to mention.

Tuesday, August 10, 2010

Paris: City of Plaster

Paris is the most civilized city in the world. This French city is built on the human scale: narrow radiating streets guarantee shadows or sun (your choice) to walk in, cafes occupy most corners, and free public self-cleaning toilets are proliferating. Trees are omnipresent, a river runs through the center of town, the yellow-ochre-tinted sandstone buildings bounce back the light. Public transportation is easy and convenient. The people are professional and friendly when approached with a "Bonjour, Madame" or "Bonjour, Monsieur."

Paris also prides itself as a source of civilization, a city of paintings and statues and elegant design. Its museums are also filled with exotic dinosaurs, extinct mammals, engineering marvels, and more. My argument here is that Paris owes much of its artistic and scientific ability to civilize the world to the deposits of gypsum on which it sits.

Gypsum is calcium sulfate dihydrate; when most of the water is driven off, powdered calcium sulfate hemihydrate is formed (the manufactured analog of the mineral bassanite). When water is added, the resulting material (plaster of Paris) can be molded, cast, carved, polished, waxed, and painted.

Oil paintings were created on canvases prepared with gesso, a plaster/glue mixture, then mounted in gilt plaster frames. Plaster completed broken statues (e.g., the second wing of the Nike of Samothrace), and was used to sculpt maquettes and molds for bronze works. (Unlike marble statues, plaster models could be added to and repaired, allowing sculptors to learn from their mistakes.) House paint was mixed with plaster to produce delicate colors, and murals were painted into not-yet-dry plaster walls. Dinosaur bones (and other heavy but delicate artifacts) were brought from distant lands, safe in their jackets of plaster.

But the most important civilizing role plaster has played is in model making and reproduction of three-dimensional items. Every major city park can have its copy of "The Thinker." Broken but scientifically important samples could be completed and mass-produced: e.g., instead of one irreplaceable Neanderthal skull, anthropologists could take measurements from individual copies at their own universities. And in case an original was lost, damaged or destroyed, copies existed to aid in restoration.

Although replaced in many of its functions by other plaster compositions, acrylics, and polymer resins, plaster of Paris was invaluable in spreading scientific and artistic knowledge, especially in the 1800s and 1900s. And Paris, the City of Enlightenment, still sits on the gypsum mines of Montmartre.

Thursday, July 29, 2010

Bees, the Arcade Game!

This is another miscellaneous post.

I live in southern California, and work in a converted porch surrounded by windows. Behind my desk and monitor is a window wall overlooking a grape arbor, and there is a hole in the wall for TV and computer cables.

It's bee season; Africanized honeybees swarm with their young queen, looking for a place to establish a hive. If they find a good location, they stay; otherwise, the swarm moves on.

One day two weeks ago, a swarm discovered our grape arbor. Which would be fine, but...
Every now and then, a bee would discover the cable port, walk in, and find herself behind my desk.
Here's the sequence:
  • The worker lands on the edge of the hole and walks in. Her feet leave a faint aroma for her peers to follow.
  • Vrrooop! She hovers up between the wall and the desk, to find herself at a window.
  • Buzz-bump-buzz-bump-etc., as she flies from my northwest corner of the room to the sunny south side.
  • (Oblivious, I'm working on my computer.)
  • A second bee lands on the edge of the cable port, finds a faint bee scent and follows...
After three bees, I figured I'd better get them out of the room. It's hard to persuade them out an open window; I succeed with one, and she tries to come back in the window I'd opened for her. The other two get the fly swatter treatment, but as they do....
  • I hear Vrrooop sounds.
There are now six bees in the room, buzzing and bumping along the windows.

They must be thinking in bee language:
"Hmm, footprints!
"I hear buzzing in there.
"Nobody's come out; hmm-mmm.
"Promising! Let's check it out."
  • Vrrooop! Vrrooop! Vrrooop! Twelve bees in the room.
I'm just waiting for some bee to let the queen know this looks good.

My sweet husband finally dodged the bees outside, took a can of foam sealant goop (recommended) and plugged the entrance hole. Then he and I got to swatting. By the next day, the swarm had passed on, and I got to vacuum away about three dozen dead bees.

Final score: Us 40 or so, Bees 0. But it could have been worse.

Monday, July 12, 2010

Miscellaneous: Heat Rash Palliative!

This has nothing to do with minerals, and is only marginal to natural history, but...

I serendipitously found something that makes heat rash quit itching and allows it to heal: Conditioner for Hair.

(Heat rash raises itchy welts on your skin, especially where any clothing binds or abrades your skin.)

You know what hair conditioner is, right? The stuff you put on your hair after you shampoo it, to make the hair smooth, shiny, and easy to comb.

I have used both Neutrogena and Pantene conditioner, but suspect others will work as well. They work for me.

To apply, just rub the conditioner on your dry skin like hand lotion, and see if it helps. If you can, apply it after a bath or shower; but it seems to work under other circumstances as well.

  • I am not a medical doctor. Please check with an MD if you have any concerns.
  • I have no stake in the success of any shampoo or conditioner company.

Tuesday, May 11, 2010

Collection Management VII: What else belongs in your records?

Some information belongs in your collection records, but not on the card accompanying the specimen. In the pre-software era, collections also had log books and catalog cards. The log book (register or catalog) usually told you, for any catalog number, the item species, location, source, and date acquired. The catalog card for each specimen contained the same information as the specimen label, with some additions:
  • Dimensions of the specimen (English, metric, or both) and of its largest crystal(s);
  • Source information: from whom, his/her address, date, price [or trade or field collection information]. If the specimen's history could be traced further back, often this was provided in the source information (or in the detailed description)
  • Detailed description of the specimen: color, minerals present, why notable. etc.
  • History of the specimen in your possession (e.g., exhibition dates)
  • Photographs or other images, or links thereto.
  • Any relevant references, to the specimen itself, the locality, the mineral species, etc.
In the computer era, various collection management software is commercially available to hold this information. Simple searchable versions can be made using Excel, or comparable spreadsheet software.

Monday, April 26, 2010

Collection Management VI: The Label, part 4 (last)

What else goes on this little label?

I write a small description of the specimen at the bottom, such as:
  • Gray metallic massive
  • Pencil-shaped crystals
  • Green, pink, and blue Xtals on matrix [Xtals = crystals]
  • Blue XOM [XOM = crystals on matrix]
  • Blue mXOM [mXOM = microscopic crystals on matrix]
  • Massive; from type locality
  • Heavy!
  • Fragile! Don't touch Xtals!
  • Water soluble white XOM
  • Poisonous gray octahedra OM
  • Radioactive yellow powdery OM
  • et cetera.

That is, the description should be a short version of anything you would say to a beginning collector who wanted to look at the specimen.


Also, you may want a border, signature, or "from the collection of..." statement on each of your labels.


I put indexing information on the back of my labels. I am a systematic collector, so the label gets the Dana numbers (from Dana's System of Mineralogy, currently in its eighth edition) for each of the minerals present.

Monday, April 19, 2010

Collection Management V: The Label, Part 3: Localities

The specimen's locality is the most crucial piece of information that can be provided. This is because a mineral's identity can always be redetermined, but its exact locality usually cannot be restored with any certainty.

I recommend that the label contain locality information in as much detail as you can provide: for mines, this includes the level, stope, cross-cut, etc.; the GPS coordinates, if you have them; address, city, township, county, state, etc. If you have not collected the specimen, all this information may not be available; the currently desired minimum information is the county (or equivalent), state (or equivalent), and country (or equivalent).

What about existing labels? I generally make my own label as well (you may want to save the old label in a separate place if it is delicate). Some locality information may be out of date (e.g., "Czechoslovakia" or "USSR").

For localities, don't add new information that did not come with the specimen, unless you can indicate on the label that you are doing so. One way is to put the new information in brackets, ideally with your initials labeling the change:
[Czech Republic]mjc, formerly Czechoslovakia

Tuesday, April 13, 2010

Tuesday Promotion: Translation and Deciphering

Speaking of labels,

Do you have any old mineral specimens whose labels make no sense to you?
They might describe strange materials (Bergkrystal, Ghassoul);
They may come from bizarre places (Styria?);
They may be written in handwriting a doctor would envy;
Or they may be written in a foreign language.

Maybe I can help! I can read technical German, Spanish, French, and Portuguese, and work my way through some Russian, Ukrainian, Latin, and Greek. I am also familiar with old styles of cursive writing and with Fraktur.

Contact me at mlj@cox.net if you could use these services. My rates are reasonable.

Monday, April 12, 2010

Collection Management IV: The Label, Part 2

Last week, I mentioned that a mineral label should accompany each specimen. It should display: a number, the mineral identity, the locality, a short description of the specimen, and possibly the mineral formula (chemistry), and a descriptor for the collection itself. I also discussed the specimen number (as used on the label). Let's look at some other items.

The mineral identity (species, possibly variety):
The standard reference used is Fleischer's Glossary of Mineral Species, published by the Mineralogical Record Press. (The 2008 edition is marred by a controversial decision by the IMA that renamed many common minerals, including those in the apatite mineral group; the decision has now been reversed, so some mineral names are already outdated.)

I tend to use variety names when they are available, such as:
Beryl, variety Emerald
Beryl, var. Emerald
Beryl v. Emerald

The next item, when present, is the Mineral Formula. You can use words:
beryllium aluminum silicate
or the chemical formula:

I usually do not include additional chemical information true for the variety in the formula (such as the presence of Cr and/or V in emerald); I put that information in the comments field, if anywhere.

Monday, April 5, 2010

Collection Management III: The Label, part 1

Traditionally, a label is a small card (e.g., 1.5 x 2 inches or 3x5 cm) that accompanies the specimen. (This discussion is not about display labels for competitive exhibits, but for those for the collection "at home.") For mineral specimens, I recommend the following contents:
  • The specimen number
  • The mineral identity (species, possibly variety)
  • Optional: the mineral formula
  • Not optional: the mineral locality information, as exactly as possible
  • A short description
  • Optional: Label design or information indicating the collection from which it comes.
Number: Each specimen has a unique number, and that number will be prominently displayed on the label. Usually, each specimen has its own label, but in some cases several very similar pieces can share the same label.
For example, one collector I know numbers several loose crystals of the same mineral from the same locality as follows: 1234-1, 1234-2, 1234, 1234-4. These can then share the same label numbered 1234, with the description including: "Four (4) loose crystals."

Monday, March 15, 2010

Collection Management - II

Each item in a collection needs:
  • a unique descriptor (e.g., specimen number),
  • an accompanying label,
  • a permanent record,
  • and safe, accessible storage.
In this post, I will discuss the unique descriptor.

Typically, this is a unique number assigned to the specimen. It may also be an alphanumeric character string, a bar code, etc.; but a symbol that requires a sophisticated scanner to read assumes that scanning system will be available for the useful life of the specimen (which may be centuries).

For minerals, this number is usually affixed to the specimens, either by writing or painting it on the specimen, or by attaching a printed label with permanent glue.

For loose gemstones, typically each gemstone has its own box, and a label with the descriptor is affixed to the box. As the label is not physically attached to the stone, it helps to include the gemstone weight on its label as a quick (but not exact) check for its identity.

Every record for this specimen should include the descriptor. Descriptor should not be used for more than one specimen (except in the case of bulk samples, where each bulk sample needs a unique descriptor, and individual grains in the sample only need separate descriptors when they are separated out for some purpose, like research or display). Descriptors should never be reused, since even if a specimen is destroyed, lost, or traded away, its records should remain with the collection.

I provide collection management services professionally, so feel free to contact me!

Thursday, March 11, 2010

What is Collection Management?

Whether you have a small mineral collection that has outgrown its single bookshelf, or a few more gemstones than fit into one box, or a large personal collection, or even a museum-grade collection of 1000 pieces or more, you probably need collection management. Let's explore what's involved in this service (which I can provide, of course).

Collection management occurs on several levels. Its main goal is to keep each specimen associated with the information that gives it value or importance. Thus, it creates and maintains linkages between the specimen and its history.

Wednesday, March 3, 2010

Minerals, Gems, and Crystals

Recently I've been giving a talk on the difference between mineralogy and gemology. (Mineralogy studies minerals, gemology studies gems; but there are other differences and similarities.)

When I explain things more than once, I keep trying to make the explanation simpler and clearer.

A mineral is defined by its (essential element) chemistry and crystal structure. There are many sites that explain this.

A gem is defined by its properties. If the gem is also a mineral, these properties are based on its essential element chemistry and crystal structure, but can also be due to:
  • Trace elements (Cr and V in emeralds, Cr in rubies)
  • Inclusions (cat's-eyes and star stones)
  • Texture (the interlocking texture in jadeite, the felted texture in nephrite)
  • Grain size and lack of inclusions, leading to diaphaneity: transparent to translucent to opaque; the greater the transparency, the greater the likelihood a sample is gem-quality.
(And some gems are not minerals: pearls, opal, jet, ivories, amber, etc.)

As a related topic, I see the term crystal used to mean different things to different people in the gem and mineral business.
  • Mineralogically, a single crystal is a connected structure retaining orientation from one end to the other. (In a mosaic crystal, sub-blocks of the structure have slightly different orientations, which can lead to large changes on orientation from one end to the other, like in saddle-shaped dolomite crystals.)
  • To an emerald dealer, "crystal" means a fine quality emerald that will hold up well to cutting.
  • To a mineral collector, a crystal should retain all its natural surfaces; but to someone in the metaphysical community, polished surfaces may be acceptable.
  • By people who deal in glass imitations, I have seen "crystal" used as it is used for glassware: a high-refractive index material (often containing lead) that would still be considered amorphous to mineralogists.
  • A crystal ball should be quartz, not glass; sometimes "crystal" is short-hand for rock crystal quartz, the colorless transparent variety.

Monday, March 1, 2010


Old friend and fellow mineralogist Vandall King recommended that I start a blog, so here it is. In future installments, I hope to tell stories about minerals and gems, so stay tuned!

But first, some words from my sponsor. My company, Mary Johnson Consulting, has a website with my background. The site, www.maryjohnsonconsulting.com, is active but updated infrequently. (The site includes some of my zoo sketches as well.)

I also have an exciting service for anyone who needs ideas about minerals, gems, their durability, curation, display, etc.: one half-hour discussion for new clients for $25. For half of the time we discuss your problem and for the remaining 15 minutes we brainstorm on possible solutions. Contact me at mlj@cox.net with BRAINSTORM as the subject line if you are interested.

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ISBN: 1435106105 or ISBN-13: 9781435106109.