fire

en-noun

fire (countable and uncountable, plural fires)

fires (plural)
fier (alternative archaic)

→ Japanese: ファイヤー (faiyā)

Sranan Tongo: faya

From Middle English fyr, from Old English fȳr (“fire”), from Proto-West Germanic *fuir, from *fuïr, a regularised form of Proto-Germanic *fōr (“fire”), ultimately from Proto-Indo-European *péh₂wr̥.
See also Saterland Frisian Fjuur, West Frisian fjoer, Dutch vuur, Low German Füer, German Feuer, Danish fyr. Also, compare Hittite 𒉺𒄴𒄯 (paḫḫur), Umbrian pir, Tocharian A/B por/puwar, Czech pýř (“hot ashes”), Russian пуры́нь (purýnʹ), Ancient Greek πῦρ (pûr, “fire”), and Armenian հուր (hur, “fire”). This was an inanimate noun whose animate counterpart was Proto-Indo-European *h₁n̥gʷnis (see ignite). Cognate to pyre.

I wouldn't piss on someone if they were on fire

pull someone's chestnuts out of the fire

there may be snow on the mountaintop but there's fire in the valley

there may be snow on the rooftop but there is fire in the furnace

you don't look at the mantelpiece when you poke the fire

you don't look at the mantelpiece when you're poking the fire

In other words, the more times a light ray reflects within a diamond, the greater the separation of the spectral colors—and the more obvious the appearance of fire—will be. Fire in a gemstone is best defined as "the visible extent of light dispersed into spectral colors" (Reinitz et al., 2001). In a polished diamond, this is seen as flares or flashes of color that appear and disappear as the diamond, the observer, or the light source moves.

2009 December, Al Gilbertson, Benjamin Gudlewski, Mary Johnson, George Maltezos, Axel Scherer, James Shigley, “Cutting Diffraction Gratings to Improve Dispersion (“Fire”) in Diamonds”, in Gems & Gemology, volume 45, number 4, Gemological Institute of America, →DOI, archived from the original on 2024-07-30, pages 260–270:

(gemology) The capacity of a gemstone, especially a faceted, cut gemstone, that is transparent to visible light, to disperse white light into its multispectral component parts, resulting in a flash of different colors, the richness and dispersion of which increases the gemstone's value.


opal

In Florio’s A World of Words 1598 as opale, from French opale, from Latin opalus, from Byzantine Greek ὀπάλλιος (opállios), from Sanskrit उपल (upala, “gem, stone”), from उपरि (upári, “the upper millstone”). Distantly related to over.

أُوبَال

a mineral consisting, like quartz, of silica, but inferior to quartz in hardness and specific gravity

(mineralogy) A mineral consisting, like quartz, of silica, but inferior to quartz in hardness and specific gravity, of the chemical formula SiO₂·nH₂O.

(gemology) A precious gem, an iridescent gemstone found in the opal-silica mineral substrate (potch)


paragon

From Anglo-Norman paragone, peragone, Middle French paragon, from Italian paragone (“comparison”) or Spanish parangón, from Byzantine Greek παρακόνη (parakónē, “whetstone”), from Ancient Greek παρακονάω (parakonáō, “I sharpen, whet”), from παρά (pará) + ἀκόνη (akónē, “whetstone”) (from Proto-Indo-European *h₂eḱ- (“sharp”)).

affix

1861 Anon ("E.L.L"): Article "Precious Stones" in "Temple Bar", a London Magazine ed. George Augustus Sala , vol. III. November 1861, p. 377. https://www.google.co.za/books/edition/Temple_Bar/3Po7AQAAMAAJ?hl=en&gbpv=1&dq=paragon+diamond&pg=PA379&printsec=frontcover
The "Koh-i-noor," or "Mountain of Light," is the eighth and smallest of these paragon diamonds (all diamonds weighing over a hundred carats are called Paragon); but it was originally the largest diamond ever known, weighing uncut 900 carats. . . It is believed that the Koh-i-noor and the Orloff are one and the same diamond, and that, if they could be reunited, they would make up the size and weight described by Tavernier, and prove to be this matchless gem of 900 carats which once belonged to the Great Mogul, and was the very paragon of paragons. Since the Mountain of Light came into the possession of the English it has been cut as a brilliant, whereby it has been still further diminished in weight, but enhanced in value and beauty. . .
Next to the Paragons come a few highly celebrated diamonds, of rare value and beauty, but below the paragon standard of a hundred carats. There is the "Shah of Persia," with its curious inscription of Indian possessors, now belonging to Russia — a long irregular prism weighing 863 carats. . .

(gemmology) A flawless diamond of at least 100 carats.


princess cut

LL-Q1860 (eng)-Flame, not lame-princess cut.wav

(gemology) A square multi-faceted cut of a gemstone.


potch

1982, Gemmological Association of Great Britain, The Journal of Gemmology, Volume 18, page 432,
Discusses the difference between potch opal and common opal. The terms are often used synonymously, but this writer shows that potch is found only in association with precious opal and differs from common opal in its structure quite substantially.

She set them down with precision, she set them down with the same kind of care that Bernie took when he and his underlings cut opal, or when they polished the rough stones, or when they bonded opal veneer on to potch.

1996, Janette Turner Hospital, Oyster, paperback edition, Virago Press, page 75:

2006, Michael O'Donoghue, Gems: Their Sources, Descriptions and Identification, 6th Edition, Elsevier, UK, page 321,
Likewise, a thin piece of good opal on potch (opal with no play of colour) may be cut so that the potch acts as a backing.

(chiefly Australia, mineralogy, gemmology) A type of rough opal without colour, and therefore not worth selling.


iolite

en-noun

iolite (countable and uncountable, plural iolites)

From Ancient Greek ἴον (íon, “violet”) + -lite.

(gemology) The clear variety of cordierite, sometimes used as a gem.


rose-cut

(gemology) Cut flat on the reverse, and with a convex face formed of triangular facets in rows; said of diamonds and other precious stones.


aventurescence

(gemology) An optical reflectance (a metallic glitter) effect seen in certain gems, arising from small, preferentially oriented mineral platelets within the material.


Ballas

(gemology, mineralogy) A variety of non-gem-grade diamond.


pineapple opal

(gemology, mining) A large raw opal spheroidal gemstone with pineapple-like projection points


opal pineapple

(gemology, mining) Alternative form of pineapple opal


black opal

(gemology, mineralogy) A rare, precious gemstone that is dark in color and is known for its play of color.


play of color

plays of color (plural)
play-of-color (alternative)
play of colour (alternative)
play-of-colour (alternative)

(gemology, mineralogy) An optical phenomenon that occurs when light interacts with a gemstone, causing it to appear to change color.


of the first water

(idiomatic, gemology) Of a diamond or other gemstone, of the highest quality or excellence.