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