Usually, There are vertical lines on the surface of the prism, and
the transect is spherical triangle. The shape of the aggregate is
like stick, emanant, or bundle of needles, and sometimes it is
dense massive or hidden crystal massive.
Generally the tourmaline is contained in the pegmatite, albite,
lepidolite, and greisen. Usually the tourmaline has the phenomenon
of colorful ribbon, with colorless line trace, luster of glass, and
cannot be separated into slice. Hardness: 7.**7.5, possessing
brittleness, specific gravity:3.***3.*5, with piezoelectricity and
pyroelectricity, the tourmaline shows no or little fluorescence
under the shining of the ultraviolet. The red one may send out
feeble purple fluorescence. Under the transmission light of the
microscope it will show pleochroism.
