Kinoite is Hydrated Calcium Copper Silicate Ca2Cu2Si3O8(OH)4, and it was first discovered here in Arizona in 1970. I photographed this large specimen at the Arizona-Sonora Desert Museum.

Kinoite, Hydrated Calcium Copper Silicate Ca2Cu2Si3O8(OH)4

Kinoite was named after Father Eusebio Francisco Kino (1645–1711), a Jesuit missionary and explorer who established many Catholic missions here in the Southwest, including a mission near Tucson in 1700, the Mission San Xavier del Bac.

Kinoite is a rather scarce mineral and is only found in a few locations around the World in association with other Copper (Cu) minerals. Many of the finest specimens come from the Christmas Mine in Gila County, Arizona. Kinoite crystals are generally very small and may form crusts of tiny crystals on rocks.

Kinoite is a light to medium pure blue color very different from other copper minerals which are either dark blue, turquoise to greenish blue, or varying shades of green. Individual crystals of Kinoite may be a bit darker, more of a medium royal blue color. Depending on the crystal formation, it has a Mohs' hardness of 2.5 to 5 (crusts to individual crystals). Kinoite is transparent to translucent and has a blue streak when scraped on an unglazed ceramic plate.