Correct Answers| Latest Update
By what date had Kokichi Mikimoto begun culturing whole pearls
1908
Synthetic gem materials
Are not minerals
which of the following is an organic gem
amber
which of the following is amorphous
amber
a natural material that's made up of a mass of one or more kinds of mineral
crystals is
rock
what group does Almandine belong to
garnet
A gem produced by, or derived from, a living organism is
,organic
which of the following is a gem variety
demantoid
the world's largest gem-consuming market is
the US
a substance that consists of atoms of only one kind is a
chemical element
Media attention in the 1990s regarding its treatment reduced consumer
confidence in
emerald
a natural, inorganic substance with a characteristic chemical composition and
usual crystal structure is a
mineral
most gems are
minerals
To be a gem, a mineral must be beautiful, durable, and
rare
,a broad gem category based on chemical composition and crystal structure is
called a
gem species
Many colored stones are mined by
independent miners using small-scale mining methods.
Rocks altered by heat and pressure beneath Earth's surface are
metamorphic
Which type of deposit is usually the most profitable for colored stone mining?
secondary
Which gem can crystallize in volcanic rock from gasses released by magma?
red beryl
Emeralds are rarely found in placer deposits because they're
unable to withstand much abrasion
Which is a workable alluvial deposit of gem minerals with economic potential?
placers
, Which is a deposit where gems eroded from the source rock and remained in
place nearby?
eluvial
from granite, pegmatite gems get exotic elements like
beryllium, boron, and lithium
Myanmar's famous Mogok ruby deposits were formed by
metamorphic process
most of the gems in Tanzania’s Umba river valley are formed in
placer deposits
A deposit where gems are found in the rock that where they formed is called
primary deposit
Which is a key locality for hydrothermal gems?
Ouro Preto, Brazil
Heat and pressure transform limestone into