“Dimensions: 2" wide in image Billowing branches of marcasite encased in clear agate. This specimen was cut into a few slabs, revealing the form of the marcasite. In addition, a white mineral, probably melanterite (listed as a mineral in San Luis Obispo Co.), is adjacent to the marcasite in a few places. Melanterite is a product of the breakdown of pyrite and marcasite. Child photos of another slice of the specimen, and the outer surface of the specimen.”

“Dimensions: 3" wide in image Billowing branches of marcasite encased in clear agate. This specimen was cut into a few slabs, revealing the form of the marcasite. In addition, a white mineral, probably melanterite (listed as a mineral in San Luis Obispo Co.), is adjacent to the marcasite in a few places. Melanterite is a product of the breakdown of pyrite and marcasite. Child photo of the outer surface of the specimen.”

“Dimensions: 3.5" x 2.75" Outer surface of a Nipomo Agate specimen, revealing the agate which has accumulated around the branches of marcasite.”