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tree resin hardened over time up to 1000 years
amber
immature amber
copal
most valuable amber
transparent red
cause amber color change over time
oxidation
circular marks sometimes left in amber when heat and oil it
sun spangles
coral most valuable color
intense red
color of conchiolin coral
black and gold
,most valuable ivory
elephant tusks
ornamental form of lignite coal
jet
major jet source
England
A natural, inorganic substance with a characteristic chemical composition and
usually characteristic crystal structure is a(n)
mineral
Which of the following is a gem variety
demantoid
A substance that consists of atoms of only one kind is a
Chemicals element
A broad gem category based on chemical composition and crystal structure is a
gem species.
,Kunzite is most often found in association with
tourmaline and beryl in pegmatite.
Myanmar's famous Mogok ruby deposits were formed by
metamorphic processes.
Most of the gems in Tanzania's Umba River Valley are found in
placer deposits
From granite, pegmatite gems get exotic elements like
beryllium, boron, and lithium.
Heat and pressure transform limestone into
marble
Which type of twinning looks as if two crystal halves are mirror images
Contact
Which type of twinning is caused by environmental change after the gem forms
Polysynthetic
A unit cell defines a mineral's
basic identity.
, Which is classified in the orthorhombic crystal system
topaz,iolite,tanzanite,chrysoberyl and peridot
Crystals that grow in a flux that is highly saturated with the necessary elements
tend to be
small
How heavy an object is in relation to its size is called its
density
Which element does chromium substitute for to cause ruby's red
Aluminum
Which element causes the color of both almandine and peridot
iron
Which components of a transition element's atoms can produce color in gems
electrons
Adularescence is caused by
scattering of light