Onyx / onyx marble
In correct usage, the name onyx refers to a black and white banded agate, a variety of chalcedony. In addition to black and white onyx,…
Category: Gem or Scam? Library
Obsidianite / emerald obsidianite
Deceptive name for man-made glass, whether mixed with volcanic ash or not, sold as natural volcanic glass. Man-made “volcanic” glass is mainly offered under the…
Ocean Jasper™
Commercially registered trade name used for a multicolored silicified rhyolite or tuff from Madagascar. In this originally volcanic rock, quartz or chalcedony and feldspar have…
Orange aventurine
Designation for a quartz variety with shimmering inclusions of a mica variety or hematite. No analysis is known. See aventurine. Do you have a nice…
Oregon Sunstone
Commercial name for a variety of labradorite, a plagioclase feldspar, with a Schiller effect (flash) with an orange/brown color from the state of Oregon, United…
Orgonite
Man-made geometric shapes of epoxy resin filled with minerals/crystals and metals. So Orgonite itself is not a mineral or gemstone, but is sometimes offered as…
Osolite Jasper
Commercial name for polychrome (multicolored) jasper. Do you have a nice example of this stone and would like to provide a photo for the library…
Opalite / opaline
A misleading trade name for man-made opalescent glass. This material looks somewhat like opal and is also frequently sold as (imitation of) real opal. In…
Ouro Verde (quartz)
Commercial name for a popular bright yellow/green variety of irradiated and heated smoky quartz. Thus the color is not natural, but treated by man. The…
Purple turquoise
Commercial name for a man-made product. These are usually natural pieces of turquoise from the Kingman Mine in Arizona that are crushed, dyed, stabilized and…
