COMMON SULPHUR. 351 fitr. 151.; the edge of the common basis is occa- O ~ nf sionally truncated *, fig. 152. 2. Octahedron, acuminated with four planes, which are set on the lateral planes f, fig. 153. The apices of the acumination are sometimes trun cated J, fig. 154. 3. Double six-sided pyramid, with two opposite broad, and four smaller, lateral planes, and which end in a line ||, fig- 155. 4. The preceding figure acuminated on the extremi ties with four planes, and the acuminating planes set on the smaller lateral planes §, fig. 150. 5. In delicate acicular crystals. The crystals are middle-sized, small, and very small, seldom large. The surface of the crystals is generally smooth, seldom drusy. Internally it is intermediate between shining and splen dent, and the lustre is adamantine, approaching to resi nous. The fracture is uneven, inclining sometimes to splin tery, sometimes to conchoidal. The fragments are angular, and blunt-edged. It is translucent; the crystals are semi-transparent and transparent, and they refract double. It is soft. It is brittle, and easily frangible. When * Sou fro pri-mc, llauy. ■f Soufrc dioiiecacdre, Hauy. £ Soufre octodecimal, Iluuy. K Soufre cmoussr, Iluuy. § Soufre umbinairc, llaur.
