"Boracite" Quotes from Famous Books
... eight thick. The crystals, perfectly transparent, were solitary, and often three or four toises distant from each other. They were enclosed in the calcareous mass, as the quartz crystals of Burgtonna,* (* In the duchy of Gotha.) and the boracite of Lunebourg, are contained in gypsum. There was no crevice near, or any vestige of calcareous spar.* (* This phenomenon reminds us of another equally rare, the quartz crystals found by M. Freiesleben ... — Equinoctial Regions of America • Alexander von Humboldt |