Home > California Borate Minerals – July 22 > MS0953 Colemanite, Celestine

Colemanite, Celestine - Sold

Colemanite is a calcium borate mineral. In 1883, Henry Hanks, the first state mineralogist of California, published an early announcement of the specie. The mineral name honors William T.Coleman (1824-1893), early developer of the borate industry in California. Colemanite is a stable mineral, in dry and humid environments. This is an excellent specimen with tan crystals to 2 cm across forming a cluster, on which a 1 cm tall radiating group of pale blue celestine crystals stands. The celestine crystals provide an excellent contrast to the tan colemanite. Quite aesthetic. Although relatively common, quality specimens of colemanite are quite rare and difficult to obtain. This is a closed locality within the Death Valley National Monument.