Tour"ma*line (?), n. [F. tourmaline,
cf. It. turmalina, tormalina, NL. turmalina,
turmalinus; all fr. tournamal, a name given to this stone in
Ceylon.] (Min.) A mineral occurring usually in three-sided or
six-sided prisms terminated by rhombohedral or scalenohedral planes. Black
tourmaline (schorl) is the most common variety, but there are also other
varieties, as the blue (indicolite), red (rubellite), also green, brown,
and white. The red and green varieties when transparent are valued as
jewels. [Written also turmaline .]
&fist; Crystals of tourmaline when heated exhibit electric polarity (see
Pyroelectric, n.). Tourmaline is also used in the
form of a polariscope called tourmaline tongs.
Tour"ma*line (?), n. [F. tourmaline,
cf. It. turmalina, tormalina, NL. turmalina,
turmalinus; all fr. tournamal, a name given to this stone in
Ceylon.] (Min.) A mineral occurring usually in three-sided or
six-sided prisms terminated by rhombohedral or scalenohedral planes. Black
tourmaline (schorl) is the most common variety, but there are also other
varieties, as the blue (indicolite), red (rubellite), also green, brown,
and white. The red and green varieties when transparent are valued as
jewels. [Written also turmaline .]
&fist; Crystals of tourmaline when heated exhibit electric polarity (see
Pyroelectric, n.). Tourmaline is also used in the
form of a polariscope called tourmaline tongs.
