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38 Cards in this Set
- Front
- Back
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For about 100 years, the DeBeers company operated as a ___ to control diamond production and sales
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monopoly
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____ was a political system in South Africa that required segregation of black, mixed race, and white citizens to maintain social and economic inequality.
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Apartheid
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What type of unique geologic process forms diamond-bearing deposits?
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Kimberlite type volcanic eruptions.
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T/F diamonds are generally a good long term investmetn because they can easily be sold for their cash value
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false, not the total value because of Debeers monoply.
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Graphitea nd Diamond are both composed of what element?
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Carbon
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The naturally occurring fertilizer guano was historically mined from what type of envrionment?
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arid coastlines.
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what type of mining is most commonly used t o recover the vast shallowly buried naturally occuring fertilizer deposits found in Florida?
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strip mining
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which of the following salts is most abundant in sea water
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Halite
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Chemical formula for diamond
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pure carbon.
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Graphite formula
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different mineral different arrangement of carbon atom
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Industrial Diamonds: ____ synthetic
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90% synthetic, means they have inclusions
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US is a major syntehtic manufacturer and importer. Syntehtic diamonds are for?
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construction building
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Kimberlite Deposits
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vertical pipes , igneous rocks formed by explosive eruptions of gases from the mantle. supersonic.
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diamond processing: mining technique?
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open pit until deep transition to underground.
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diamond concentrated by?
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density separation, cyclone separator
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round diamonds cut -- how are diamonds shaped?
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can only be cut by other diamonds. only hardest material
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Diamond Value 4 C's
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Clarity
Carat Cost Color |
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Clarity
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How clear a diamond is, how much you can see through it translucent -- milky or cloudy, devalue
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Color
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how bright, how clear ever so slightly yellow or off white or blue
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Carat
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the unit of weight for gem stones karat(quality of gold) carat with C is 2/10 of gram
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why is Hope Diamond a little blue?
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because it has Boron
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De Beers is a ? how do they control?
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cartel, they control a big enough portion of the market largest influenceo n the industry through distrubtion and price. control through 1. central selling organization and 2. advertising.
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US official diamond policy?
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no conflict diamonds -- only import diamonds with good relation countries (but they prob got it from blood diamond)
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Blood Diamond
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civil wars in African countries using mininng to fund their civil wars
non blood diamond countries: india, belgium, israel <-but they get their diamonds from blood countries |
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Diamond Versus Graphite
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Graphite - common
soft low-density form of carbon Diamond - rare dense high pressure form of hard carbon |
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US diamond mines?
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U.S. has one historic mine in AK
no active mines |
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diamonds mined by surface mining?
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Placer deposits:
< 40% of natural diamond production mined by dredging decreasing production environmental concerns falling recovery |
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Sortex machine
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concentrate is exposed to X-rays -
Diamonds fluoresce Machine “sees” the diamonds and activate air jets blowing diamonds into a bin |
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Grease table
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diamonds are hydrophobic - they stick to oil
Concentrated ore is washed over a greased surface Diamonds stick to the grease and are recovered |
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how much of raw weight of diamond is lost when crystal is cut and polished?
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1/2 of the raw weight is lost when the crystal is
cut and polished |
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which color diamonds are most common? represented by which letters?
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colorless DEF
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clarity-- which have inclusions that u can see
which have inclusions you can't see? |
SI and I grades are the lowest - visible inclusions
VVS and VS grades: inclusions that cannot easily seen with the naked eye |
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A Diamond is Forever" campaign BECAUSE OF ?
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GREAT DEPRESSION
1939 -Great Depression caused diamond prices to plummet De Beers launched a massive advertising program in the USA: |
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other gemstone value criteria
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Color, luster, transparency, durability, rarity
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the most valuable (non-diamond) gemstones?
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Emeralds, rubies, sapphires: the most valuable (non-diamond) gemstones
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Gemstone Ruby and Saphirea re of the same mineral and different varieties TF
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false,
Ruby: Red aluminum oxide called Corundum Sapphire - Blue (and other non-red) Corundum same variety Emerald and Aquamarine -- same mineral, different variety. (blue variety vs green variety.) |
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volcanic rocks where diamond deposits are found form at what rate?
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kimberlite pipes form at very rapid (supersonic) Kimberlite eruptions
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industrial diamonds are used to make special cutting tools because they are
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harder than gem quality diamonds
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