sinhalite

sinhalite

[′sin·ə‚līt]
(mineralogy)
MgAl(BO4) A mineral composed of magnesium aluminum borate; sometimes used as a gem.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.
References in periodicals archive ?
Desautels, in fact, was still the Curator when the taxpayers in question donated a variety of specimens to the Smithsonian, among them, a sinhalite, a cat's-eye rubellite tourmaline, a couple of euclase crystals, several cerussite specimens, some wulfenite specimens and a few anglesite crystals.
Surveying this latter table, one wishes (if one is a mineral collector) that certain gem materials of "non-traditional" type, listed here, had been awarded chapters of their own: benitoite, brazilianite, euclase, sinhalite, or even sphalerite might justly have claimed more text-space (we think, if we are mineral collectors) than chalcedony or amber, each of which gets a large chapter.
As mineral species go, even gem-potential species, diamond is not really rare--how many tons of jeremejevite or sinhalite do you suppose have been found?--but its enduring appeal, not to speak of its many industrial uses, makes the securing of further supplies a pressing concern.
In addition to these, Mountain Minerals has also acquired a number of other interesting new items from Sri Lanka, including some exceptionally sharp sapphire crystals to 4 cm from Galbkka, near Vallivaya, Uva Province; terminated crystals of pinkish zircon up to 3.5 cm that resemble those from the Canadian Grenville Province occurrences from Amlilipitiya, near Kataragama; shiny black octahedral spinel crystals to 1 cm from Monaragala, near Badulla, Uva Province; and a 27-carat, 2-cm crystal of sinhalite from Nirialla, near Ratnapura, Sabaragamuwa Province.
Euhedral sinhalite crystals, reported here from Sri Lanka for the first time, have yielded morphological data in agreement with that previously published for a crystal from Burma.
Sinhalite, MgAlB[O.sub.4], is among the rarest of the 30 or so gem minerals found in the alluvial gem deposits of Sri Lanka.
A pale pink to brownish pink, chromian variety of sinhalite has been reported in millimeter-size grains from a skam occurrence in the Kwakonje area of the Handeni district in northeast Tanzania (von Knorring, 1967; Bowden et al., 1969).
Although commonly represented in collections of rare gems in sizes up to 240 carats (Arem, 1977; Koivula et al., 1993), sinhalite is not often seen in mineral collections.
Synthetic sinhalite (Werding et al., 1981) is orthorhombic and shows {100} and {011} as dominant forms with {101} and {102} present less frequently.
The faces of the sinhalite crystals are finely pitted, which we attribute to etching rather than abrasion.
A small fragment, measuring 45 x 58 x 178 [[micro]meter], was removed from the damaged region of sinhalite crystal #1.
The pattern obtained contained 19 measurable reflections which are consistent with literature values for natural and synthetic [TABULAR DATA FOR TABLE 1 OMITTED] sinhalite (Claringbull and Hey, 1952; Schaller and Hildebrand, 1955; and Capponi et al.