abundant
acidic
avg
batteries
beautiful
black
black background
brass
cathode
chemical process
common
copperas
crystal
cube
cuboid
dioxide
energizer
fools gold
gemstone
geologic
geological
geology
gold
hue
ignition
industry
inexpensive
iridescent
iron
isolated on black
isometric
jewel
jewelry
marcasite
material
mineral
oxidation
oxides
pale
pretend
pyrite
reflection
reflective
resemblance
semiconductor
shine
shiny
silver
sulphide
yellow