Nipomo Agate is also sometimes referred to as Marcasite Agate, these designer milky white semi translucent agate cabochons have golden metallic Marcasite and Pyrite inclusions. This gemstone material is pretty rare.
Marcasite and Pyrite are both forms of iron sulfide. Marcasite and Pyrite can form in Agate during volcanic activity.
Marcasite and Pyrite are often confused, and in fact the name Marcasite comes from the Arabic word for Pyrite, marqashith.
Nipomo Agate collecting areas were on private land and have been closed to collecting for more than 40 years and old sources are getting scarce. Unfortunately in the 1960's this is one area where discourteous rockhounders ruined it for everybody. They trampled farmers fields, left gates open or closed them leaving cattle unable to get to water, etc.
Agate is a member of the chalcedony family, or a microcrystalline quartz, and it has a hardness of about 7 on the Moh's scale. The name Agate is derived from its occurrence at the Achates River in southwestern Sicily.
In general Agates are said to be stabilizing and strengthening. It is believed they improve memory and increase energy. Marcasite is said to help prevent exhaustion and burn-out during trying times.