A very rich micro specimen from the early 1970's of Nasonite in Datolite from Merehead Quarry, Somerset, England. The Nasonite forms prominent rich blue areas to 4mm length, contrasting well against the white platy radial Datolite. Nasonite is a rare Lead Calcium Sorosilicate Chloride only found at very few locations around the world. (Sorosilicates belong to a class where two tetrahedra share an oxygen atom).