Assignment 4a - Diamond Exploration

Question 1

What are the different types of diamond deposits?

Answer 1

• Primary deposits
• Secondary deposits (alluvial & marine)

Question 2

What type of deposit produces the majority of diamonds mined today?

Answer 2

Most diamonds mined today come from primary deposits.

Question 3

Gems found in the rock that carried them to the surface

Answer 3

Primary deposit

Question 4

Gems found away from their primary source

Answer 4

Secondary deposit

Question 5

A deposit where gems are eroded from their source rock, then transported away from the source and further concentrated

Answer 5

Alluvial deposit

Question 6

Secondary diamond deposit carried by rivers or streams to the ocean floor or shoreline

Answer 6

Marine deposit

Question 7

How do geologist locate diamond sources?

Answer 7

• Select a craton
• Narrowing search via air and ground
• Locate pipes
• Test diamond content (Microsampling, Character sampling, bulk sampling)

Question 8

What tests determine a mine’s potential?

Answer 8

To determine a mine’s potential mining companies evaluate three factors:
- Size of deposit
- Concentration of rough diamonds (ore grade)
- Size & quality of diamonds

Question 9

Minderals that form along with diamonds at great depths and are brough to the surface by the same kimberlite or lamproite

Answer 9

Indicator minerals

Question 10

Screening for the presence of tiny diamonds in a sample

Answer 10

Microdiamond testing

Question 11

Testing for the size, shape, clarity and color of the diamonds in a deposit (500 tons)

Answer 11

Character sampling

Question 12

Large-scale character sampling (5-10’000 tons)

Answer 12

Bulk sampling

Question 13

An analysis that determines the chemical composition of a sample

Answer 13

Geochemical testing

Question 14

The concentration of diamonds in a deposit, measured by the amount of diamonds in 100 tons of earth removed

Answer 14

Ore grade

Question 15

A quantity of stones, sometimes of similar size and quality, packaged together for sale or storage

Answer 15

Parcel.

Question 16

What type of survey measures rock density in search of diamond deposits?

Answer 16

Gravity

Question 17

What quality of diamonds do secondary deposits typically contain?

Answer 17

Diamonds are more concentrated in secondary deposits and secondary deposits contain a higher percentage of gem-quality diamonds than primary deposits.