Thursday, July 11, 2013

What color is it? My hair is turning gray.

My hair is turning gray. (The color is only called grey when it describes a horse.)

Recently I examined two samples of cut hair, one from the end of a cubit-long ponytail, recently cut off; the other from six-inch sideburns of the same vintage. Like a horse, I am graying from the nose to the tail; in this case, from the temples to the nape of my neck.

Least gray hair: Munsell 7.5 YR 3/4 in Daylight-Equivalent Illumination
Grayest hair: Munsell 7.5 YR 5/2. The hue stays the same, but tone lightens and saturation decreases, as one would expect.


The illustration shows ponytail and sideburn hair and Munsell color chips, as taken with my scanner. The scanner's illumination is not the same as Daylight-Equivalent Fluorescence (the standard for using Munsell color chips), so the color match may not seem accurate.

Monday, June 10, 2013

What's it worth? Valuing unique specimens (part 1)

When I was an undergraduate, I took a course in Macroeconomics. This is the study of How Money Works, nationally and internationally (and is no help whatsoever for balancing a check book). One learns early that money is not a fixed quantity--that it can be created and destroyed. One also learns that money is a medium of exchange, and not an innate measure of value.

Instead, prices are set by supply and demand. When a commodity is widely available compared to the demand for it, prices are low. When a commodity is scarce and people want a lot of it, prices go up. For many gemstones, for which size and quality can be specified, prices are stable enough that price lists are useful for relaying market prices.

But what about unique items? If there is considerable demand, the selling price may be very high: more than $33 million was bid for a particular Oriental rug, as a recent example. And if demand is nonexistent, the price is irrelevant: in that case, the value might as well be zero.

Appraisers and insurers use the term Fair Market Value (FMV). The IRS defines FMV as: "the price that would be agreed on between a willing buyer and a willing seller, with neither being required to act, and both having reasonable knowledge of the relevant facts" (from IRS publication 561,

In practice, it is commonly recommended that rare items can best achieve their FMV at auction. However, auction prices for individual items may not be representative for various reasons. Perhaps the auction was not widely advertised to interested parties. (One I attended in the 1980s occurred during a snowstorm, which enabled me to get some excellent mineral specimens at very reasonable prices.) Conversely, sometimes bidders get over-excited--or over-competitive--and certain items are bid to astronomical prices. (Charity auctions are a likely place for this behavior.) Because of these factors, I sometimes say that prices at auction indicate how much the person who wanted an item second-most was willing to pay: that is, the highest losing bid sets the value. On a case-by-case basis, the market may behave irrationally.

Of course, the solution to this is to look at many examples, not just one. Consider the appraisal of houses Perhaps you live in a century-old house that is rather unique. There are no exact comparisons--in size, location, age, construction, view, landscaping, distance to schools, etc.--currently on the market that would set the value for this house. So a real estate agent, or insurance appraiser, or tax appraiser, does not look at every factor that sets the approximate value of the house. Instead, they consider certain basic factors -- neighborhood, house size, lot size, etc. to set a value; and use the other factors that may make the house unique -- a remodeled kitchen, a view, general condition -- to add or subtract a premium to that base price.

How does this apply to appraising mineral specimens? See Part 2, to come at some point....

Friday, June 7, 2013

It's been a while....

Since I last posted on this site. Since I last updated my profile, I've been to the Arctic Ocean in Canada (Tuktoyaktuk); and since I last posted, I've been to Tahiti (in transit), two of the Tuamotos, and all six inhabited Marquesas Islands. Perhaps at some point I will write about those.

Tuesday, March 27, 2012

Untangling a Necklace

My mother was a woman with a frequently flamboyant personal style. She wore long jackets, scarfs, and multiple necklaces, usually of costume jewelry. Nearly 20 years ago, I inherited a necklace of imitation cinnabar lacquer beads that was hopelessly entangled with another necklace. 

Why “hopelessly?” Well, the second necklace consisted of three strands of closely-spaced rectangular black plastic beads, resembling very long zipper teeth strong on strong thread. The beads were far enough apart to easily get tangled up with each other, and close enough together for any knots to be nearly impossible to see, much less untie. The three 50-inch-long strands could not be separated from each other at either side of the clasp. 

Here is how I untangled this black necklace:

The tangles could be described as having two components: knots and loops. At the knots, two strand sections were intertwined between pairs of beads. Loops were larger structures in which a section of a strand was wrapped around another part of the necklace.

I examined all the knots, and loosened each one, confirming that, at least locally, the strings could move relative to each other. Trying to move loops was very frustrating, though, as a tangle in one spot might be resolved, while a few more were created as the tooth-like beads interacted with each other elsewhere in the necklace. The loops had to be made to slide across each other, not catch on each other.

I therefore used "Saran Wrap" to wrap up free loop sections, and blue contractor’s tape to seal the ends of the wrapped sections (figure 2). As I untangled the knots, I added to the wrapped areas. Eventually almost all the necklace was wrapped, and the untangling was complete.

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, 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.