GIA Diamonds and Diamond
Grading Assignment 3
Questionnaire Comprehensive
Questions (Frequently Tested)
with Verified Answers Graded
A+
Where are cratons generally found? - Answer: Center of landmasses
Cratons are the oldest and most geologically stable parts of the earth's landmasses. These
regions are usually in the middle of a continent and don't experience earthquake activity. Most
diamond deposits, still in the rocks that brought them to the surface, are found either on
cratons or in the areas surrounding them. See "Cratons and Mantle Keels" in Diamonds &
Diamond Grading Assignment 3.
How can crustal diamonds form? - Answer: Meteorite impacts
Crustal diamond is a rare diamond that forms in the continental crust at or near the earth's
surface due to meteorite impact or tectonic plate collision. This can occur when plates collide,
often at boundaries between continental plates. See "Crustal Diamonds" in Diamonds &
Diamond Grading Assignment 3.
What results from kimberlite or lamproite eruptions? - Answer: Pipes
What remains is a diamond-bearing pipe: a deep vertical formation that results from a
kimberlite or lamproite eruption. See "Arrival at the Surface" in Diamonds & Diamond Grading
Assignment 3.
Grading Assignment 3
Questionnaire Comprehensive
Questions (Frequently Tested)
with Verified Answers Graded
A+
Where are cratons generally found? - Answer: Center of landmasses
Cratons are the oldest and most geologically stable parts of the earth's landmasses. These
regions are usually in the middle of a continent and don't experience earthquake activity. Most
diamond deposits, still in the rocks that brought them to the surface, are found either on
cratons or in the areas surrounding them. See "Cratons and Mantle Keels" in Diamonds &
Diamond Grading Assignment 3.
How can crustal diamonds form? - Answer: Meteorite impacts
Crustal diamond is a rare diamond that forms in the continental crust at or near the earth's
surface due to meteorite impact or tectonic plate collision. This can occur when plates collide,
often at boundaries between continental plates. See "Crustal Diamonds" in Diamonds &
Diamond Grading Assignment 3.
What results from kimberlite or lamproite eruptions? - Answer: Pipes
What remains is a diamond-bearing pipe: a deep vertical formation that results from a
kimberlite or lamproite eruption. See "Arrival at the Surface" in Diamonds & Diamond Grading
Assignment 3.
