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pyrophane
pyrophane n.
Brit. 
/ˈpʌɪrə(ʊ)feɪn/
, /ˈpʌɪrə(ʊ)feɪn/U.S. /ˈpaɪrəˌfeɪn/
[ < pyro- comb. form + -phane comb. form] Mineralogy (now rare) a mineral said to become translucent or to show colour when warmed, esp. a form of opal with this property, made by impregnating hydrophane with wax; (also, partly by confusion) any of several other varieties of opal./ˈpaɪrəˌfeɪn/ΘΚΠ
society > occupation and work > materials > raw material > gem or precious stone > opal > [noun] > varieties of
girasol1588
oculus mundi1661
eye of the world1730
hydrophane1784
cacholong1791
pitchstone1794
pyrophane1794
semi-opal1794
fire opal1811
sun opal1818
isopyre1827
alumocalcite1832
jasper-opal1843
opal jasper1848
resin opal1850
pitch opal1861
jasp-opal1868
opal-agate1868
harlequin1873
harlequin opal1887
wax-opal1896
potch1897
pinfire1902
moss opal1904
nobby1919
the world > the earth > minerals > types of mineral > silicates > tectosilicate > [noun] > quartz > amorphous quartz or opal > others
girasol1588
oculus mundi1661
hydrophane1784
cacholong1791
pitchstone1794
pyrophane1794
semi-opal1794
wood-stone1794
fire opal1811
wood-opal1816
sun opal1818
isopyre1827
jasper-opal1843
opal jasper1848
resin opal1850
natural glass1853
pitch opal1861
vitrite1866
jasp-opal1868
opal-agate1868
pearl opal1872
harlequin1873
harlequin opal1887
wax-opal1896
potch1897
moss opal1904
nobby1919
1794 R. Kirwan Elements Mineral. (ed. 2) I. 291 It is said that some pyrophanes are found in Armenia, which are transparent while exposed to the sun, and opake at night.
1892 E. S. Dana J. D. Dana's Syst. Mineral. (ed. 6) 195 Pyrophane is a name..given to a kind [of opal] which by the absorption of melted wax is made translucent when hot, but becomes opaque again on cooling. The name has also been used for Fire-opal.
1997 A. W. Eckert World of Opals vi. 180 Pyrophane. A type of precious opal in which the POC [= play of colour] appears to wander about haphazardly and appear at random... The name pyrophane is also at times incorrectly applied to both girasol opal and hydrophane opal.
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