Diamonds

Question 1

graphite to diamonds

Answer 1

crystallised to form octahedral

Question 2

two uses of diamonds in industry

Answer 2

mining

or cutting and polishing for jewellery

Question 3

carat = 0.2 grams worth?

Answer 3

$1000s

Question 4

1997 production worth?

Answer 4

US$7Bn

Question 5

2008 production worth?

Answer 5

US$9Bn

Question 6

Diamond producing countries

Answer 6

S Africa

Botswana

Question 7

diamond importing

Answer 7

EU, India

Question 8

average diamond price is?

Answer 8

declining

Question 9

De Beers 4 Cs

Answer 9

Carat
Colour
Clarity
Cut 
= COST

Question 10

diamonds produced in ? countries

Answer 10

21

Question 11

Gem producers

Answer 11

RSA, Namibia, Botswana, Russia

Question 12

Industrial producers

Answer 12

Australia, Botswana, DRC

Question 13

Central Selling Organisation (CSO) - De Beers

Answer 13

to maintain price (high) and stability (rhodes). Includes 80% of global trade

Question 14

stockpiling

Answer 14

$2-5Bn

Question 15

1949-1990 price of diamonds ^

Answer 15

1800%

Question 16

geochemistry of kimberlites

Answer 16

Ultramafic MgO >12/15%
Ultrapotassic
REE enrichment
LILE enrichment
High CO2 and H2O
Primitve Ni, Cr, Co

Question 17

Kimberlite pipe

Answer 17

2km deep, magma ascends 70km/h,
highest grade on crater rim
82 degree slope

Question 18

xenocrysts

Answer 18

a crystal in an igneous rock which is not derived from the original magma.

Question 19

diamond bearing kimberlites found in

Answer 19

thick continental crust of archean age

Question 20

presence of diamonds in kimberlites

Answer 20

30%, 1% mineable

Question 21

origin of kimberlites

Answer 21

depths below 150km, rapid ascent to avoid conversion to graphite, presence of coesite suggests depth