Ajoite has the chemical formula (Na,K)Cu7AlSi9O24(OH)6·3H2O,[6] and minor Mn, Fe and Ca are usually also present in the structure.

He found specimens of dark blue shattuckite, together with a bluish green mineral which he suspected was a new species.

[8] Twenty three years later, in 1981, George Chao from Carleton University in Ottawa, Canada, studied the mineral again, and showed that ajoite was triclinic, and not monoclinic as had been thought previously.

Ajoite is translucent and bluish green in color, with a pale greenish white streak and a vitreous luster.

[4][6] Ajoite is named after its type locality, the New Cornelia Mine in the Ajo District of Pima County, Arizona.

Type material is conserved at the National Museum of Natural History, Washington DC, US, reference number 113220.

Other localities include Wickenburg and Maricopa County in Arizona, within the United States, and the Messina (Musina) District in South Africa.