In veinlets and on fracture surfaces in metalimestones, formed during cooling of a high-temperature calc-silicate assemblage under oxidizing conditions
IMA Status:
Approved IMA 1977
Locality:
In the Christmas copper mine, Christmas, Gila Co., Arizona, USA. Link to MinDat.org Location Data.
Name Origin:
For Joe Ana Ruiz, of Mammoth, Arizona, USA, collector of microscopic minerals, who discovered the mineral.