pyrochloren.

Brit.

/ˈpʌɪrə(ʊ)klɔː/, U.S.

/ˈpaɪroʊˌklɔr/

Forms: 1800s pyrochlor, 1800s– pyrochlore.

Origin: A borrowing from German. Etymon: German Pyrochlor.

Etymology: < German Pyrochlor ( F. Wöhler 1826, in Ann. der Physik u. Chemie 7 417) < pyro- pyro- comb. form + ancient Greek χλωρός greenish-yellow (see chloro- comb. form¹).

Mineralogy.

A niobium-containing mineral found chiefly in nepheline-syenite and pegmatitic rocks, and occurring as brown or yellowish octahedral crystals which may turn green (or other colours) when strongly heated. Also: any of a group of oxide minerals sharing the cubic (isometric) crystal structure of this mineral and containing niobium, tantalum, or titanium. Frequently attributive, esp. in pyrochlore group.The members of the pyrochlore group have the general formula A₂B₂O₆ or A₂B₂O₇, where A may be sodium, potassium, calcium, barium, uranium, or certain other elements, and B may be niobium, tantalum, titanium, or certain other elements. The mineral pyrochlore is a niobate, hydroxide, and fluoride of calcium and sodium, (Ca,Na)₂Nb₂O₆(OH,F). Crystal structure: cubic.

ΘΚΠ

the world > the earth > minerals > types of mineral > oxides and hydroxides > [noun] > oxides of titanium, tantalum, nickel, or rare earths > pyrochlore or microlite

pyrochlore1830

microlite1835

neotantalite1903

pandaite1959

bariopyrochlore1977

1830 Amer. Jrnl. Sci. 18 392 Pyrochlor, from Norway, in zircon sienite.

1866 P. H. Lawrence tr. B. von Cotta Rocks Classified i. i. 45 Pyrochlore occurs as an accessory in granite and syenite.

1906 J. P. Iddings Rock Minerals ii. 464 Pyrochlore group. Pyrochlore, RNb₂O₆.R(Ti,Th)O₃.NaF. Koppite, R₂Nb₂O₇.²/ ₅NaF. Microlite, Ca₂Ta₂O₇.pt. (Pyrrhite).

1959 E. Jäger et al. in Mineral. Mag. 32 24 Some authors prefer to include under pyrochlore all the members of the group. Others give distinct names to the various members of this group.

1977 Amer. Mineralogist 62 404/1 The pyrochlore group comprises those multiple cubic oxides having the following characteristics: (a) essential amounts of niobium, tantalum, and titanium, either individually or in combination (b) the space group Fd3m, (c) the pyrochlore structure as defined by Gaertner (1930) and Brandenberger (1931) [etc.].

1993 Jrnl. Petrol. 34 947 The liquid became saturated in phases in which these elements are compatible, such as zircon and pyrochlore.

This entry has been updated (OED Third Edition, December 2007; most recently modified version published online March 2022).

单词	pyrochlore
释义	pyrochloren. Brit. /ˈpʌɪrə(ʊ)klɔː/, U.S. /ˈpaɪroʊˌklɔr/ Forms: 1800s pyrochlor, 1800s– pyrochlore. Origin: A borrowing from German. Etymon: German Pyrochlor. Etymology: < German Pyrochlor ( F. Wöhler 1826, in Ann. der Physik u. Chemie 7 417) < pyro- pyro- comb. form + ancient Greek χλωρός greenish-yellow (see chloro- comb. form¹). Mineralogy. A niobium-containing mineral found chiefly in nepheline-syenite and pegmatitic rocks, and occurring as brown or yellowish octahedral crystals which may turn green (or other colours) when strongly heated. Also: any of a group of oxide minerals sharing the cubic (isometric) crystal structure of this mineral and containing niobium, tantalum, or titanium. Frequently attributive, esp. in pyrochlore group.The members of the pyrochlore group have the general formula A₂B₂O₆ or A₂B₂O₇, where A may be sodium, potassium, calcium, barium, uranium, or certain other elements, and B may be niobium, tantalum, titanium, or certain other elements. The mineral pyrochlore is a niobate, hydroxide, and fluoride of calcium and sodium, (Ca,Na)₂Nb₂O₆(OH,F). Crystal structure: cubic. ΘΚΠ the world > the earth > minerals > types of mineral > oxides and hydroxides > [noun] > oxides of titanium, tantalum, nickel, or rare earths > pyrochlore or microlite pyrochlore1830 microlite1835 neotantalite1903 pandaite1959 bariopyrochlore1977 1830 Amer. Jrnl. Sci. 18 392 Pyrochlor, from Norway, in zircon sienite. 1866 P. H. Lawrence tr. B. von Cotta Rocks Classified i. i. 45 Pyrochlore occurs as an accessory in granite and syenite. 1906 J. P. Iddings Rock Minerals ii. 464 Pyrochlore group. Pyrochlore, RNb₂O₆.R(Ti,Th)O₃.NaF. Koppite, R₂Nb₂O₇.²/ ₅NaF. Microlite, Ca₂Ta₂O₇.pt. (Pyrrhite). 1959 E. Jäger et al. in Mineral. Mag. 32 24 Some authors prefer to include under pyrochlore all the members of the group. Others give distinct names to the various members of this group. 1977 Amer. Mineralogist 62 404/1 The pyrochlore group comprises those multiple cubic oxides having the following characteristics: (a) essential amounts of niobium, tantalum, and titanium, either individually or in combination (b) the space group Fd3m, (c) the pyrochlore structure as defined by Gaertner (1930) and Brandenberger (1931) [etc.]. 1993 Jrnl. Petrol. 34 947 The liquid became saturated in phases in which these elements are compatible, such as zircon and pyrochlore. This entry has been updated (OED Third Edition, December 2007; most recently modified version published online March 2022). < n.1830
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