and Answers Graded A+
1. By what date had Kokichi Mikimoto begun culturing whole pearls: 1908
2. Synthetic gem materials: Are not minerals
3. which of the following is an organic gem: amber
4. which of the following is amorphous: amber
5. a natural material that's made up of a mass of one or more kinds of
mineral crystals is: rock
6. what group does alamandine belong to: garnet
7. A gem produced by, or derived from, a living organism is: organic
8. which of the following is a gem variety: demantoid
9. the world's largest gem-consuming market is: the US
10. a substance that consists of atoms of only one kind is a: chemical eleme
11. Media attention in the 1990s regarding its treatment reduced
consumer confidence in: emerald
12. a natural, inorganic substance with a characteristic chemical
composition and usual crystal structure is a: mineral
13. most gems are: minerals
14. To be a gem, a mineral must be beautiful, durable, and: rare
15. a broad gem category based on chemical composition and crystal
struc- ture is called a: gem species
16. Many colored stones are mined by: independent miners using small-
scale mining methods.
17. Rocks altered by heat and pressure beneath Earth's surface are:
metamor- phic
18. Which type of deposit is usually the most profitable for colored
,GIA Colored Stone Final Exam Test Questions
and Answers Graded A+
stone mining?: secondary
19. Which gem can crystallize in volcanic rock from gasses released by
mag- ma?: red beryl
20. Emeralds are rarely found in placer deposits because they're:
unable to withstand much abrasion
21. Which is a workable alluvial deposit of gem minerals with economic
poten- tial?: placers
22. Which is a deposit where gems eroded from the source rock and
remained in place nearby?: eluvial
23. from granite, pegmatite gems get exotic elements like: beryllium, boron,
and lithium
24. Myanmar's famous Mogok ruby deposits were formed by:
metamorphic process
25. most of the gems in tanzania's umba river valley are formed in:
placer deposits
26. A deposit where gems are found in the rock that where they
formed is called: primary deposit
27. Which is a key locality for hydrothermal gems?: Ouro Preto, Brazil
28. Heat and pressure transform limestone into: marble
29. which gem form by metamophosis: tanzanite
30. Most gemstones form in the: continental crust
31. kunzite is most often associated with: tourmaline and beryl in pegmatites
32. how heavy an object is in relation to its size: density
33. A two-phase inclusion is a cavity in a gem that's typically filled with a:
, GIA Colored Stone Final Exam Test Questions
and Answers Graded A+
liquid and a gas
34. which type of twinning is caused by environmental change after a
gem forms: polysynthetic
35. which element caused red in ruby and green in emerald: chromium
36. A unit cell defines a mineral's: basic identity
37. which type of twinning looks as if two crystal halves are mirror images:
contact twinning
38. crystals that grow in a flux that is highly saturated with the
necessary elements tend to be -: small
39. which is classified in the orthorhombic crystal system: topaz
40. Which gems are cryptocrystalline aggregates?: Chalcedony and turquois
41. Atoms in a gem that aren't part of its essential chemical
composition are called: trace elements
42. Many fashioned rubies have shallow proportions because they're cut from
: flattened crystals
43. Rough spinel often occurs as: twinned crystals
44. Needles of actinolite found in emerald are classified as: inclusions
45. which aggregates crystals are visible only under very high magnificatio
: cryptocrystalline
46. the trace elements that cause corundum's blue are: iron and titanium
47. what element does chromium substitute for to cause ruby's red: aluminiu
48. In many blue sapphires, the intervalence charge transfer that
causes the color is between: iron and titanium
49. The pattern of dark vertical lines or bands shown by certain gems
when viewed through a spectroscope is called: absorption spectrum