kornerupine

from The Century Dictionary.

• noun A silicate of aluminium and magnesium, MgAl₂SiO₆, occurring in from colorless to white fibrous or columnar aggregates: found at Fiskernäs, Greenland. Prismatine, from Waldheim, Saxony, is a similar mineral.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun mineralogy A rare boro-silicate mineral with the chemical formula (Mg,Fe2+)4(Al,Fe3+)6(SiO4,BO4)5(O,OH)2, some varieties of which are valued as gemstones.