BERYLLONITE, a mineral phosphate of beryllium and sodium (NaBePO,), found as highly complex orthorhombic crys tals and as broken fragments in the disintegrated material of a granitic vein at Stoneham, Maine, where it is associated with felspar, smoky quartz, beryl and columbite. The crystals vary from colourless to white or pale yellowish, and are transparent with a vitreous lustre ; there is a perfect cleavage in one direction. Hardness 54-6 ; specific gravity