DATOLITE POCKET, MILLINGTON QUARRY, MILLINGTON, NEW JERSEY, USA (small cabinet)

Datolite is classified as a calcium boron hydroxide nesosilicate, with the chemical formula CaBSiO4(OH). It was initially discovered by Jens Esmark in 1806, who derived its name from the Greek words δατεῖσθαι, meaning "to divide," and λίθος, meaning "stone," reflecting the mineral's granular structure.

This mineral crystallizes in the monoclinic system, resulting in prismatic crystals and nodular formations. It exhibits a vitreous luster and can appear in various colors, including brown, yellow, light green, or colorless. Datolite has a Mohs hardness of 5.5 and a specific gravity ranging from 2.8 to 3.0.

Former John Betts Collection NY # 12149