Agate
Argillite
Argillite
Argillite is a clay-rich sedimentary rock (mudstone) that is relatively soft and therefore easily carved.
Azurite
Azurite
Azurite is a secondary copper mineral with a deep blue color, and is commonly found alongside malachite, a green copper mineral.
Chert
Galina
Hematite
Kaolin
Lignite (Jet)
Lignite (Jet)
Lignite is a variety of coal formed either directly from wood (zyloid lignite) or from compressed plant materials (compact or perfect lignite). When used in jewelry, lignite is more commonly called jet.
Limonite
Limonite
Limonite is yellow-orange-brown iron ore commonly used in prehistoric pigments. When ground, limonite produces yellow ochre and darker, earthy tones. Heated, the ore changes partially to hematite, and therefore can also be used to produce red ochres and red-hued browns.
Malachite
Malachite
Malachite is a secondary copper mineral that tends to form in clusters resembling bunches of grapes. The mineral is green and is commonly found alongside azurite, a blue copper mineral.
Obsidian