GEMS 331 EXAM QUESTIONS WITH
VERIFIED ANSWERS. A+ GRADE
2025/2026.
The refractive index (RI) of a gem relates to light as it ___. - ANS enters or exits the surface of
a gemstone
Brilliance is described as ___. - ANS the amount of light reflected from within the stone
Diamond has a hardness of ___. - ANS 10
The bottom-most facet of a gemstone is called _____. - ANS The culet
Rubies and sapphires are made of ___. - ANS Aluminum Oxide (Al2O3)
Rubies are red due to ___, while sapphires are blue because of___. - ANS Chromium ions,
Titanium and Iron ions
Synthetic Rubies are made from _____ while Ruby simulants are _____. - ANS Aluminum
oxide, Spinel
Corundum has a hardness of - ANS 9
1 @COPYRIGHT 2025/2026 ALLRIGHTS RESERVED
,Pleochroism is - ANS the change of colors when viewed from different angles
Which of the following would best indicate you have a synthetic ruby? - ANS Curved striae on
surface of stone.
Peridot is a gem variety of - ANS Olivine
Beryl will not form without the presence of what element? - ANS Beryllium
The chemical structure of Olivine is - ANS (Mg, Fe)2SiO4
Which of the following statements about fire in gemstones is false? - ANS Fire is created
when facets of a cut gemstone are parallel to each other.
Color in gems may come from _____. - ANS inclusion, and reflection of specific colors
A one (1) carat diamond is worth more than a two (2) carat diamond if: - ANS Compared to
the two carat gem, the one carat gem has proper facets, and is quite clear
A four carat diamond (A) will be worth more than another of the same weight (B) if: -
ANS The second diamond (B) has cracks or appears cloudy.
(This is the only answer that makes diamond (A) more valuable. This is another aspect of the "4
C's" concept. The more clear a gem is, the more valuable it will be.)
The term 'metamorphism' refers to: - ANS the process by which rocks are changed by heat
and pressure
Pegmatites are ___. - ANS igneous rocks with very large crystals (more right)
hydrothermal deposits with large crystals
2 @COPYRIGHT 2025/2026 ALLRIGHTS RESERVED
, "Cleavage" refers to the tendency of a mineral - ANS to break along planes of atomic
weakness
Refraction - ANS to bend light as it passes from air to the crystal
Igneous rocks are ___. - ANS formed from hot, molten rock or magma
Metamorphic rocks are - ANS sedimentary or igneous rocks changed by elevated
temperature and pressure
A well cut stone should - ANS internally reflect light at the pavilion facets (The light is
reflected back up, and passes out of the top of the gemstone (the crown))
The mantle is ___. - ANS the semi-solid layer of rock below the crust (whether it's semi-solid,
semi-hard, semi-soft, or plastic, it means that it does not behave as a brittle solid.)
The cut of a stone refers to: - ANS The way a gem is faceted
The emerald cut is so named because: - ANS the namesake stone is commonly fashioned
that way
The brilliant cut is primarily used... - ANS ...to enhance the sparkle of a diamond.
Diamond is the hardest mineral. Graphite is the softest mineral. They both are made from ___. -
ANS Carbon
One carat equals ____ grams. - ANS 0.2
3 @COPYRIGHT 2025/2026 ALLRIGHTS RESERVED
VERIFIED ANSWERS. A+ GRADE
2025/2026.
The refractive index (RI) of a gem relates to light as it ___. - ANS enters or exits the surface of
a gemstone
Brilliance is described as ___. - ANS the amount of light reflected from within the stone
Diamond has a hardness of ___. - ANS 10
The bottom-most facet of a gemstone is called _____. - ANS The culet
Rubies and sapphires are made of ___. - ANS Aluminum Oxide (Al2O3)
Rubies are red due to ___, while sapphires are blue because of___. - ANS Chromium ions,
Titanium and Iron ions
Synthetic Rubies are made from _____ while Ruby simulants are _____. - ANS Aluminum
oxide, Spinel
Corundum has a hardness of - ANS 9
1 @COPYRIGHT 2025/2026 ALLRIGHTS RESERVED
,Pleochroism is - ANS the change of colors when viewed from different angles
Which of the following would best indicate you have a synthetic ruby? - ANS Curved striae on
surface of stone.
Peridot is a gem variety of - ANS Olivine
Beryl will not form without the presence of what element? - ANS Beryllium
The chemical structure of Olivine is - ANS (Mg, Fe)2SiO4
Which of the following statements about fire in gemstones is false? - ANS Fire is created
when facets of a cut gemstone are parallel to each other.
Color in gems may come from _____. - ANS inclusion, and reflection of specific colors
A one (1) carat diamond is worth more than a two (2) carat diamond if: - ANS Compared to
the two carat gem, the one carat gem has proper facets, and is quite clear
A four carat diamond (A) will be worth more than another of the same weight (B) if: -
ANS The second diamond (B) has cracks or appears cloudy.
(This is the only answer that makes diamond (A) more valuable. This is another aspect of the "4
C's" concept. The more clear a gem is, the more valuable it will be.)
The term 'metamorphism' refers to: - ANS the process by which rocks are changed by heat
and pressure
Pegmatites are ___. - ANS igneous rocks with very large crystals (more right)
hydrothermal deposits with large crystals
2 @COPYRIGHT 2025/2026 ALLRIGHTS RESERVED
, "Cleavage" refers to the tendency of a mineral - ANS to break along planes of atomic
weakness
Refraction - ANS to bend light as it passes from air to the crystal
Igneous rocks are ___. - ANS formed from hot, molten rock or magma
Metamorphic rocks are - ANS sedimentary or igneous rocks changed by elevated
temperature and pressure
A well cut stone should - ANS internally reflect light at the pavilion facets (The light is
reflected back up, and passes out of the top of the gemstone (the crown))
The mantle is ___. - ANS the semi-solid layer of rock below the crust (whether it's semi-solid,
semi-hard, semi-soft, or plastic, it means that it does not behave as a brittle solid.)
The cut of a stone refers to: - ANS The way a gem is faceted
The emerald cut is so named because: - ANS the namesake stone is commonly fashioned
that way
The brilliant cut is primarily used... - ANS ...to enhance the sparkle of a diamond.
Diamond is the hardest mineral. Graphite is the softest mineral. They both are made from ___. -
ANS Carbon
One carat equals ____ grams. - ANS 0.2
3 @COPYRIGHT 2025/2026 ALLRIGHTS RESERVED
