Chemistry: Decomposition product of plagioclase feldspar (mainly albite and zoisite).
Crystal system: Rock; massive.
Color: Opaque; often green variegated; whitish, grey green, yellow green, bluish green.
Hardness: 6.5
Cleavage: -
Specific gravity: 3.0 – 3.4 (may be as low as 2.8 if little zoisite present)
Refractive index: 1.70 (to as low as 1.57; variable; mean reading)
Luster: -
Dispersion: -
Dichroism: -
Occurrence: Mineral aggregate formed as hydrothermal alteration product of plagioclase feldspar; named after the Swiss explorer Horace Benedict de Saussure, who discovered it on the slopes of Mont Blanc.
Notes
May look like jadeite, nephrite or zoisite; cabochon, carvings.
Sunday, August 05, 2007
Saturday, August 04, 2007
Stock Market vs Gem Market
Here is what Warren Buffet says about stock market (s):
We do not have an opinion about where the stock market, interest rates, or business activity will be a year from now. We've long felt that the only value of stock forecasts is to make fortune tellers look good. We believe that short-term market forecasts are poison and should be kept locked up in a safe place, away from children and also from grown-ups who behave in the market like children.
True. Stock markets, like gem markets are always prone to extremes of elation and panic attacks. They are interpenetrant twins of the real world. As Warren Buffett put it wisely, it takes 20 years to build a reputation and five minutes to ruin it. If you think about that, you'll do things differently. Not always. A friend of mine in the gem industry would tell me this: I love money + gemstones more than the things it can buy, but what I love more is other people's gemstones + money + he would say, I'm not your best friend. I'm your only friend. How do you like that?
We do not have an opinion about where the stock market, interest rates, or business activity will be a year from now. We've long felt that the only value of stock forecasts is to make fortune tellers look good. We believe that short-term market forecasts are poison and should be kept locked up in a safe place, away from children and also from grown-ups who behave in the market like children.
True. Stock markets, like gem markets are always prone to extremes of elation and panic attacks. They are interpenetrant twins of the real world. As Warren Buffett put it wisely, it takes 20 years to build a reputation and five minutes to ruin it. If you think about that, you'll do things differently. Not always. A friend of mine in the gem industry would tell me this: I love money + gemstones more than the things it can buy, but what I love more is other people's gemstones + money + he would say, I'm not your best friend. I'm your only friend. How do you like that?
To Kill A Mocking Bird
Memorable quotes from the movie:
Atticus Finch (Greogry Peck): If you just learn a single trick, Scout, you'll get along a lot better with all kinds of folks. You never really understand a person until you consider things from his point of view... Until you climb inside of his skin and walk around in it.
Atticus Finch (Greogry Peck): If you just learn a single trick, Scout, you'll get along a lot better with all kinds of folks. You never really understand a person until you consider things from his point of view... Until you climb inside of his skin and walk around in it.
Winning Decisions
Good Books: (via Emergic) J. Edward Russo and Paul Schoemaker’s Winning Decisions book focusses on getting it right the first time.
From the book’s description:
Decision-making is a business skill which managers often take for granted in themselves and others but it's not as easy as some might think. The authors, whose expertise has been sought out by over a hundred companies, including Arthur Andersen, Hewlett-Packard, IBM, and Unilever, contend that decision-making, like any other skill, must be developed and honed if it is to be used effectively. Winning Decisions offers step-by-step analyses of how people typically make decisions, and provides invaluable advice on how to improve your chances of getting your next big decision right the first time. The book is packed with worksheets, tools, questionnaires, case studies, and anecdotes analyzing major decisions made by organizations like British Airways, NASA, Shell Oil, and Pepsi. Some of the proven, straightforward techniques covered in Winning Decisions include how to:
- Reframe issues to ensure that the real problem is being addressed
- Improve the quality and quantity of your options
- Convert expert yet conflicting opinions into useful insights
- Make diversity of views and conflict work to your advantage
- Foster efficient and effective group decision-making
- Learn from past decisions--your own and those of others
Here is what Publisher’s Weekly wrote about Winning Decisions (published in 2001):
The coauthors of 1989's Decision Traps offer a clear, straightforward explanation of how managers should perform one of their most basic tasks: making a decision. Russo, professor of marketing and behavior science at Cornell, and Shoemaker, research director of Wharton's Mack Center for Technology and Innovation, break their method into four steps: framing decisions, i.e., factoring in difficulties like information overload and the "galloping rate of change," and thereby determining which choices need to be addressed and which ones don't; gathering real intelligence, not just information that will support internal biases; coming to conclusions, i.e., assessing how one's company acts on the intelligence gathered; and learning from experience. The authors walk readers through each of the steps. Unlike many business books, this one is akin to a workbook, providing how-tos, case studies and worksheets so readers can put their ideas into play immediately. The authors highlight key concepts, and they even show an occasional humorous side. However, they stress that even improving the way one goes about making decisions won't guarantee that they'll be the right ones. Decisions still have to be executed successfully, and luck is always a factor. Still, with better decision-making skills, the odds are bound to go up.
I think the book highlights traits of cognitively swift entrepreneurs of tomorrow. It's a must-read book.
From the book’s description:
Decision-making is a business skill which managers often take for granted in themselves and others but it's not as easy as some might think. The authors, whose expertise has been sought out by over a hundred companies, including Arthur Andersen, Hewlett-Packard, IBM, and Unilever, contend that decision-making, like any other skill, must be developed and honed if it is to be used effectively. Winning Decisions offers step-by-step analyses of how people typically make decisions, and provides invaluable advice on how to improve your chances of getting your next big decision right the first time. The book is packed with worksheets, tools, questionnaires, case studies, and anecdotes analyzing major decisions made by organizations like British Airways, NASA, Shell Oil, and Pepsi. Some of the proven, straightforward techniques covered in Winning Decisions include how to:
- Reframe issues to ensure that the real problem is being addressed
- Improve the quality and quantity of your options
- Convert expert yet conflicting opinions into useful insights
- Make diversity of views and conflict work to your advantage
- Foster efficient and effective group decision-making
- Learn from past decisions--your own and those of others
Here is what Publisher’s Weekly wrote about Winning Decisions (published in 2001):
The coauthors of 1989's Decision Traps offer a clear, straightforward explanation of how managers should perform one of their most basic tasks: making a decision. Russo, professor of marketing and behavior science at Cornell, and Shoemaker, research director of Wharton's Mack Center for Technology and Innovation, break their method into four steps: framing decisions, i.e., factoring in difficulties like information overload and the "galloping rate of change," and thereby determining which choices need to be addressed and which ones don't; gathering real intelligence, not just information that will support internal biases; coming to conclusions, i.e., assessing how one's company acts on the intelligence gathered; and learning from experience. The authors walk readers through each of the steps. Unlike many business books, this one is akin to a workbook, providing how-tos, case studies and worksheets so readers can put their ideas into play immediately. The authors highlight key concepts, and they even show an occasional humorous side. However, they stress that even improving the way one goes about making decisions won't guarantee that they'll be the right ones. Decisions still have to be executed successfully, and luck is always a factor. Still, with better decision-making skills, the odds are bound to go up.
I think the book highlights traits of cognitively swift entrepreneurs of tomorrow. It's a must-read book.
Painting By Numbers
Peter Schjeldahl profiles Gustave Courbet @ http://www.newyorker.com/arts/critics/books/2007/07/30/070730crbo_books_schjeldahl
Slides And Prejudice
Linda Yablonsky writes about new generation artist's concept (s) based on photo-based painting (s) + the new technology + other viewpoints @ http://artnews.com/issues/article.asp?art_id=2020
De Beers At The Mall Of The Emirates
Chaim Even-Zohar writes about Dubai and the Mall the Emirates + wholesale vs retail market sector + De Beers and DTC supported brands + other viewpoints @ http://www.idexonline.com/portal_FullEditorial.asp?TextSearch=&KeyMatch=0&id=25546
Heavy Liquids
For the purpose (s) of identifying gems it is not usually so important to obtain an exact SG determination because most gems have a plus or minus range of SG. An approximate value is just useful as an exact value. For this reason, heavy liquids offer the gemologist what is considered by most to be the best overall method of SG determination available.
When a gem is put into a liquid of lower density than its own, it will sink. If the stone’s density is less than that of the liquid, it will float. Or if the stone’s density is exactly equal to that of the liquid, it will suspended, neither sinking nor floating. So it can be seen that by using a range of liquids with known densities it is possible to estimate the specific gravity of a gem. By noticing the speed with which a gem sinks or floats in a liquid, an accurate estimate can be made regarding the difference between the specific gravity of the liquid and the stone.
Types Of Heavy Liquids
The heavy liquids today consist of methylene iodide (pure SG=3.32) diluted with varying amounts of benzyl benzoate (pure SG=1.12) to obtain values below 3.32. The main advantage of using benzyl benzoate to dilute the methylene iodide instead of xylene (toluene), which was used in the past, is that the evaporation rates for methylene iodide and benzyl benzoate are nearly equal and so the density of the mixture is fairly constant and does not need to be adjusted as often as mixtures using xylene.
Methylene iodide: 3.32
Bromoform: 2.89
Benzyl benzoate: 1.12
Xylene (toluene): 0.87
Clerici’s solution: 4.15
Clerici’s solution is a concentrated solution in water of thallium formate and thallium malonate. It is expensive, poisonous and rather dangerous to handle compared with other liquids, but with a density of about 4.15 it is easy to forget about these shortcomings. Many find it useful to dilute Clerici’s solution (with water) to about 4.00 which is the SG of corundum.
Of all the heavy liquids, methylene iodide is undoubtedly the most useful. With a pure SG of 3.32 and of equal importance, an R.I (refractive index) of 1.74, it can serve two purposes: testing SG and immersion. Upon exposure to light, methylene iodide has a tendency to turn brown or black, but if a small piece of copper is kept in the bottle this darkening process can be reversed.
When a gem is put into a liquid of lower density than its own, it will sink. If the stone’s density is less than that of the liquid, it will float. Or if the stone’s density is exactly equal to that of the liquid, it will suspended, neither sinking nor floating. So it can be seen that by using a range of liquids with known densities it is possible to estimate the specific gravity of a gem. By noticing the speed with which a gem sinks or floats in a liquid, an accurate estimate can be made regarding the difference between the specific gravity of the liquid and the stone.
Types Of Heavy Liquids
The heavy liquids today consist of methylene iodide (pure SG=3.32) diluted with varying amounts of benzyl benzoate (pure SG=1.12) to obtain values below 3.32. The main advantage of using benzyl benzoate to dilute the methylene iodide instead of xylene (toluene), which was used in the past, is that the evaporation rates for methylene iodide and benzyl benzoate are nearly equal and so the density of the mixture is fairly constant and does not need to be adjusted as often as mixtures using xylene.
Methylene iodide: 3.32
Bromoform: 2.89
Benzyl benzoate: 1.12
Xylene (toluene): 0.87
Clerici’s solution: 4.15
Clerici’s solution is a concentrated solution in water of thallium formate and thallium malonate. It is expensive, poisonous and rather dangerous to handle compared with other liquids, but with a density of about 4.15 it is easy to forget about these shortcomings. Many find it useful to dilute Clerici’s solution (with water) to about 4.00 which is the SG of corundum.
Of all the heavy liquids, methylene iodide is undoubtedly the most useful. With a pure SG of 3.32 and of equal importance, an R.I (refractive index) of 1.74, it can serve two purposes: testing SG and immersion. Upon exposure to light, methylene iodide has a tendency to turn brown or black, but if a small piece of copper is kept in the bottle this darkening process can be reversed.
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