Sturmanite, Ettringite, Charlesite
N'Chwaning II Mine, N'Chwaning Mines, Kuruman, Kalahari manganese fields, Northern Cape Province, South Africa
Small Cabinet, 5.4 x 2.4 x 1.7 cm
A SUPERB, LARGE and glassy yellow-brown crystal that exhibits all three members of the solid solution series of sturmanite, ettringite and charlesite from the famous Nchwaning II Mine. This undamaged crystal has sturmanite and charlesite on the outside and ettringite on the inside of the crystal. It has a few stepped growth elements on the edges that show one internal member of the series, charlesite, under the sturmanite coating (those spots are not damage). The backlit photo highlights the translucency and yellow-cored interior composed of the lemon-yellow ettringite. 5.4 x 2.4 x 1.7 cm