GEM230-final

All questionare questions and answers to study/memorize

Wholesale price lists are usually organized according to

Specific combinations of the 4 C’s

Large, high-quality diamonds are

graded much more thoroughly than small, low-quality ones.

A diamond’s clarity and color grades indicate its

quality

Substantial price discounts are available to retailers and jewelry manufacturers who

can buy in large quantities.

The diamond industry has changed dramatically in recent years because

the world’s supply of diamond rough has increased.

A diamond grading system provides

a consistent way to communicate diamond quality.

Dealers often sort melee by size using

sieves

Diamond prices on wholesale price lists

depend on the market conditions that exist when the lists are published.

The Argyle mine in Australia contributed to

the rise of the cutting industry in India.

A wholesaler is someone who

sells to retailers.

Diamond’s supreme hardness and durability are

a result of the conditions under which it formed.

The most consistent and dependable sources of diamond grades are

reputable gemological laboratories.

Reputable gem laboratories don’t grade mounted diamonds because

mountings hide details of clarity and cut.

An estimation of the value of an article is a(n)

appraisal

Once diamond deposits are located, mining companies

must spend additional time and money to evaluate and develop them.

Before the discovery of South Africa’s diamond deposits, the world’s two major producers were India and

Brazil

The Diamond Information Center and the Diamond Promotion Service were created to

assist in diamond marketing efforts.

The soft, diamond-bearing material near the surface of a diamond field was named

yellowground.

Cecil Rhodes’ main competitor in his early attempts to control diamond production was

Barney Barnato.

In the diamond trade, the word “specials” refers to

diamond rough over 10.80 cts.

Who established De Beers Consolidated Mines Ltd. in 1888?

Cecil Rhodes

De Beers Consolidated Mines Ltd. was named after

the owners of a farm where one of the first diamond rushes took place.

Sightholders purchase diamond rough by

attending invitation-only trading events.

De Beers requires its sightholders to have an excellent reputation in the industry and

the financial strength to make large purchase commitments.

Diamond sources started appearing in South Africa during the

1860s.

The group that united in 1890 to buy and sell all of the output of the major diamond producers, including De Beers, was the

London Diamond Syndicate.

The path diamonds followed from mine to consumer was called the

diamond pipeline.

The South African diamond rush was sparked by

the discovery of the Star of South Africa.

The Central Selling Organisation was a

rough diamond distribution agency.

Oppenheimer’s answer to low diamond demand in the 1930s was to

shut down operations at De Beers mines.

The involvement of a business or industry in all aspects of its product’s market is called

vertical integration.

In South Africa, a new mining charter that designates the people of the country as the owners of its mineral resources is a result of

Black Economic Empowerment.

A commitment to reserve a portion of the resources derived from any country for the economic development of that country is called

beneficiation

Which diamond mine’s huge production influenced the world market in the late 1980s?

Argyle

Because the Australians believed the CSO’s marketing favored large stones over smaller ones, they

aggressively promoted jewelry set with their own tiny gems.

Vast quantities of small, inexpensive diamonds suitable for low-cost, mass-market jewelry are mined in

Australia

De Beers became a privately owned company in

May 2001.

A bourse is a(n)

diamond buying and selling club.

The program adopted by De Beers in 2007 to answer critics and resolve shortcomings of its SOC program is called

Supplier of Choice 2.

The diamond industry program designed to ensure that diamonds do not fund civil conflict or terrorism is called

the Kimberley Process.

In 2000, De Beers altered its consumer advertising by

introducing the “Forevermark” logo.

Businesses that sell to consumers via television cable, phone line, or satellite are called

electronic retailers.

A city, region, or country with a large number of gemstone manufacturers is called a

cutting center.

By 2004, more than 90 percent of manufacturing for the diamond market was done in

India

One of the changes that resulted from De Beers’ strategic review in 1999 was that De Beers

changed the name of the CSO to the DTC.

During emplacement, if diamonds are exposed to high temperature along with decreased pressure for a long period, they will

convert to graphite.

The large, stable parts of the earth’s continental crust are called

cratons.

The proper environment for diamond formation includes the right temperature, pressure and

the availability of carbon.

Subduction occurs when

two of the earth’s crustal plates collide.

The correct conditions for diamond formation exist under

cratons

The first authenticated diamond discovered in South Africa is named the

Eureka.

The deep vertical formations through which diamonds traveled to the surface are called

pipes

Before arriving at the earth’s surface, diamonds might remain in the mantle for as long as a few

hundred million years.

Diamond is hard and graphite is soft because of the difference in

the way their atoms fit together.

Most of the world’s kimberlite pipes

do not contain diamonds in profitable quantities.

Diamonds were delivered to the earth’s surface as recently as

20 million years ago.

How far beneath the earth’s surface do diamonds form?

90 to 140 miles (140 to 220 kilometers)

Scientists have found that diamonds form in two types of rocks, called

peridotite and eclogite.

Diamond and graphite are both made of

carbon

The three main components of the earth are the crust, mantle, and

core

Indicator minerals in kimberlite and lamproite include tiny

diamonds

Only a small percentage of known diamond deposits are mined because most

are not profitable.

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Diamond rough suitable for use in tools, drills, and abrasives is

industrial quality.

A profitable mine

produces diamonds whose value is higher than the mine’s operating costs.

Diamond deposits found at the ocean’s shore are

marine deposits.

A mine’s potential profitability depends in part on

its ore grade.

The first step in exploring for diamonds is to

look for the oldest parts of the earth’s crust.

For more than 2,000 years, the only known diamond sources were

alluvial.

Diamond rough suitable for use in jewelry is called

cuttable

Diamonds are more concentrated in

marine deposits.

Most of the diamonds mined today come from

pipes.

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The concentration of diamonds within a pipe is called

ore grade.

Gravity sorting separates diamonds from

lighter materials.

To focus their search for diamond deposits, geologists look for

indicator minerals.

Diamonds classified as cuttable can be 100 times more valuable than

industrial diamonds.

Removal of mineral-bearing ore from a surface excavation is called

open-pit mining.

The shift in emphasis from alluvial to primary diamond mining was due to

improved technology.

Dirt and clay are washed from diamond-bearing ore by

scrubbers.

Most diamonds from Australia are

small and poor in quality.

African diamonds are recovered from

pipe, alluvial, and marine deposits.

The largest percentage of world diamond production (by weight) is mined in

Australia

Russia’s significant diamond deposits are in

Siberia

Diamond’s attraction to grease is used in

separating diamond from ore gravels.

Dense media separation is based on the fact that

diamonds sink to the bottom of a mix of gravels.

Russia’s diamond sources are almost all

primary

Most modern diamond-mining operations are

large in scale and extremely expensive.

Chambering and block caving are methods used in

mining diamond pipes.

Shortly before the discovery of the South African deposits, the world’s major diamond producer was

Brazil

The Argyle mine is famous for diamonds that are

pink

A horizontal tunnel drilled through a diamond pipe is called a

drift

What is the specific gravity of gem-quality diamond?

3\.52

Another name for the cubic crystal system is

isometric

A naturally occurring, inorganic substance with a characteristic chemical composition and usually a characteristic crystal structure is known as a

mineral

The crystal planes most suitable for cleaving a diamond are the

octahedral planes.

A flat, triangular twinned diamond crystal is called a

macle

Atoms in a gem that aren’t part of its essential chemical composition are called

trace elements.

Crystal shape is an important factor in the evaluation of rough because

it affects the amount of weight retained after cutting.

The strongest of all atomic bonds are called

covalent

The habit of gem-quality diamond is the

octahedron

In diamonds, cleavage is caused by

relatively wide spaces between some atomic planes.