[Named after Prof. G. Troost of Nashville, Tennessee: see -ITE1.]

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  1.  Min. A variety of WILLEMITE, with admixture of iron and manganese, occurring in reddish hexagonal crystals.

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1835.  C. U. Shepard, Treat. Min., II. 247. Troostite … is found at Sterling (N. J.) associated with Franklinite.

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1850.  Ansted, Elem. Geol., Min., etc., § 448. Troostite, or Troolite, is a variety [of Bi-silicate of Manganese] containing iron.

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1868.  Dana, Min. (ed. 5), 262. Willemnite … Silicate of Zinc…. The crystals of … New Jersey are often quite large, and pass under the name of troostite.

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  2.  Metallurgy. A transitional constituent of steel: cf. MARTENSITE, PEARLITE 2, SORBITE2.

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1902.  Encycl. Brit., XXIX. 572/2. Austenite, troostite, sorbite, and other constituents [of iron] have also been described.

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  Hence Troostitic a., pertaining to or consisting of troostite (Cent. Dict. Suppl., 1909).

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