black
block
chiaroscuro
classic
clear
collection
contrast
crude
crystal
crystalline
crystallization
crystals
dark
druse
exhibit
faceted
facets
gem
geology
glass
glassy
holder
isolated
jewel
jewelry
jewels
mineral
mineralogy
mountain
museum
natural
object
optic
pebble
quartz
raw
rock
science
semiprecious
shade
silica
spot light
stone
transparent
white