Diamonds & diamond grading final exam
Questions and Correct Answers, With Complete
Verified Solution. 100% Correct 2024.
Bourse
A diamond buying and selling club
- they have them in trading centers
Peridotite
A type of rock that diamonds form in
- igneous rock ( formed from a molten state)
- most diamond form in this rock
- has consistent release of carbon
Eglogite
A type of rock that diamond form in
- metamorphic rock (rocks that have been altered by heat and pressure
- does not have a consistent release of carbon
How far beneath the earth do diamonds form?
90-140 miles (140-220 kilometers)
Drift
A horizontal tunnel drilled through a diamond pipe
De Beers Consolidated Mines Ltd. was named after
the owners of a farm where one of the first diamond rushes took place.
The Central Selling Organization (CSO)
A rough diamond distribution agency
- served as this until 2001
Pipes
The deep vertical formations through which diamonds travel to the surface
Chambering
An older underground mining technique
- expensive & dangerous so no longer used
- block caving is the alternative to this
Most of the diamonds that come from Africa are recovered from
pipe, alluvial, and marine deposits
Most of the diamonds that come from Russia are recovered from
Primary Sources
What is the specific gravity of a gem-quality diamond?
3.52
Diamonds are more concentrated in which type of deposit?
Marine deposits
The first step in exploring for diamonds is to
look for the oldest parts of the earth's crust
The diamond industry has changed dramatically in recent years because
, the world's supply of diamond rough has increased
- this means diamonds are available to more people
The Argyle mine in Australia contributed to the rise of the cutting industry in
India
What is the softest crystal direction in diamond?
Dodecahedral
What crystal system does diamond belong to?
Isometric or cubic crystal system
What are diamond's 3 internal crystal planes?
Cubic ( runs horizontal), octahedral (on face), dodecahedral (runs vertical)
The crystal planes most suitable for cleaving a diamond are the
octahedral planes
Another name for the cubic system is
isometric
Blocker
Polishes the crown and pavilion mains
Brillianteering
Polishing of the star & upper and lower half facets
Bezel facets are the ones shaped like
kites
star facets are the ones shaped like
triangles next to table
Upper half facets are the ones
on the outer edge next to the girdle
Visible light is a form of
radiant energy
Grease on the pavilion of a diamond results in
more light leakage through the pavillion
The rotary saw contributed to the diamond cutting industry by
allowing for greater weight retention from rough
A surface indentation with tiny, root-like feathers penetrating the stone is called a
Bruise
Inclusions are usually most visible when they're located
directly under the table
A stone with only a few extra facets on its pavilion that can't be seen face-up
should be graded
Flawless
Diamonds with minute inclusions that range from difficult to very difficult to see
under 10X are classified
VVS1 or VVS2
Pit
blemish- A small opening that looks like a tiny white dot at 10x
Knot
an included diamond crustal that extends to the surface after fashioning
Cavity
Questions and Correct Answers, With Complete
Verified Solution. 100% Correct 2024.
Bourse
A diamond buying and selling club
- they have them in trading centers
Peridotite
A type of rock that diamonds form in
- igneous rock ( formed from a molten state)
- most diamond form in this rock
- has consistent release of carbon
Eglogite
A type of rock that diamond form in
- metamorphic rock (rocks that have been altered by heat and pressure
- does not have a consistent release of carbon
How far beneath the earth do diamonds form?
90-140 miles (140-220 kilometers)
Drift
A horizontal tunnel drilled through a diamond pipe
De Beers Consolidated Mines Ltd. was named after
the owners of a farm where one of the first diamond rushes took place.
The Central Selling Organization (CSO)
A rough diamond distribution agency
- served as this until 2001
Pipes
The deep vertical formations through which diamonds travel to the surface
Chambering
An older underground mining technique
- expensive & dangerous so no longer used
- block caving is the alternative to this
Most of the diamonds that come from Africa are recovered from
pipe, alluvial, and marine deposits
Most of the diamonds that come from Russia are recovered from
Primary Sources
What is the specific gravity of a gem-quality diamond?
3.52
Diamonds are more concentrated in which type of deposit?
Marine deposits
The first step in exploring for diamonds is to
look for the oldest parts of the earth's crust
The diamond industry has changed dramatically in recent years because
, the world's supply of diamond rough has increased
- this means diamonds are available to more people
The Argyle mine in Australia contributed to the rise of the cutting industry in
India
What is the softest crystal direction in diamond?
Dodecahedral
What crystal system does diamond belong to?
Isometric or cubic crystal system
What are diamond's 3 internal crystal planes?
Cubic ( runs horizontal), octahedral (on face), dodecahedral (runs vertical)
The crystal planes most suitable for cleaving a diamond are the
octahedral planes
Another name for the cubic system is
isometric
Blocker
Polishes the crown and pavilion mains
Brillianteering
Polishing of the star & upper and lower half facets
Bezel facets are the ones shaped like
kites
star facets are the ones shaped like
triangles next to table
Upper half facets are the ones
on the outer edge next to the girdle
Visible light is a form of
radiant energy
Grease on the pavilion of a diamond results in
more light leakage through the pavillion
The rotary saw contributed to the diamond cutting industry by
allowing for greater weight retention from rough
A surface indentation with tiny, root-like feathers penetrating the stone is called a
Bruise
Inclusions are usually most visible when they're located
directly under the table
A stone with only a few extra facets on its pavilion that can't be seen face-up
should be graded
Flawless
Diamonds with minute inclusions that range from difficult to very difficult to see
under 10X are classified
VVS1 or VVS2
Pit
blemish- A small opening that looks like a tiny white dot at 10x
Knot
an included diamond crustal that extends to the surface after fashioning
Cavity
