Quartz
AmethystCabochon amethyst
13.18 carats
© Palagems
Quartz Gemstones by Colour
This table shows the variety of hues this gemstone can be found in. Click on a photo for more information.
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Quartz Gemstones by Size
This table shows distribution of Quartz gemstone sizes that are listed on this site. This can give a good indication as to the general availability of this gemstone in different sizes.
Contributed photos
Lightest:1.81 cts
Heaviest:79.25 cts
Average:15.10 cts
Total photos:87
Do you have a larger Quartz? Why not upload a photo?
| General Information | ||||||||||||||||||||||||||||||||||||||||||||||
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| Varieties/Types: | Amethyst - A purple variety of Quartz. Ametrine - A mixture of Amethyst and Citrine in the same crystal. Aventurine - A variety of Quartz containing glistening fragments, usually of mica, but sometimes hematite, goethite or chlorite. Chalcedony - A cryptocrystalline variety of Quartz. Agate - A banded variety of Chalcedony. Iris Agate - An iridescent variety of Agate. Onyx - A monochromatic Agate with black and white banding. Sardonyx - A monochromatic Agate with red/brown and either black or white banding. Binghamite - Chatoyant Chalcedony with fibres of hematite/goethite. Bloodstone - A dark green/greenish-blue Chalcedony with small red blood-like spots. Carnelian - A red to orange variety of Chalcedony. Chrome-Chalcedony - Emerald green Chalcedony, colored by chromium. Chrysoprase - A green Chalcedony coloured by inclusions of Ni minerals. Fire Agate - A variety of Agate containing iridescent spheroids of limonite. Jasper - Jasper is a dense, opaque, microcrystalline variety of Chalcedony. Dallasite - A variety of Jasper from Vancouver Island, British Columbia, Canada. Orbicular Jasper - Jasper containing numerous spherical inclusions. Moss Agate - A translucent Chalcedonly containing green strands of chlorite. Petrified Wood - A decorative type of fossil wood where the original organic material has been replaced - usually by chalcedony, agate, opal, etc. Sard - A brown to brownish-red translucent variety of Chalcedony. Citrine - A yellow to yellow-orange or yellow-green variety of Quartz. Prase - Prase is a leek-green variety of Quartz. Prasiolite - A green variety of Quartz. Rock Crystal - A transparent colourless variety of Quartz. Rose Quartz - Pink variety of Quartz. Rutilated Quartz - A clear Quartz shot through with golden needles of Smoky Quartz - Smoky-grey, brown to black variety of Quartz. Morion - Sometimes synonymous with Smoky quartz, but often reserved for nearly black Smoky quartz. Tiger's Eye - Chatoyant yellowish-brown variety of Quartz. Falcon's Eye - Trade name for a blue variety of Tiger's Eye. | |||||||||||||||||||||||||||||||||||||||||||||
| Chemical Formula |
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| Synthetic Quartz | ||||||||||||||||||||||||||||||||||||||||||||||
| All colors, mostly amethyst, citrine, ametrine: colors are usually intense. Standard tests limited: needle-like 2 phase inclusions, dust-like "breadcrumb" planes, whitish wisps. In synthetic quartz, if present, twinning may create a distinctive lfame-like pattern or may be seen as very thin parallel lines showing interference colors with diagnostic striated appearance. Synthetic blue: Chelsea - red. - Blue Chart Gem Identification, Herve Nicolas Lazzarelli, 2010, p 7 Synthetic quartz: mostly untwinned, rarely triangular sectors with interference colours, "bread crumbs", residues of the seed plate - Gemmological Tables, Ulrich Henn and Claudio C. Milisenda, 2004, p 9 | ||||||||||||||||||||||||||||||||||||||||||||||
| Physical Properties of Quartz | ||||||||||||||||||||||||||||||||||||||||||||||
| Mohs Hardness | 7, Gemmological Tables (2004) More from other references | |||||||||||||||||||||||||||||||||||||||||||||
| Specific Gravity | 2.65, Gemmological Tables (2004) More from other references | |||||||||||||||||||||||||||||||||||||||||||||
| Cleavage Quality | None, Gemstones (2009) | |||||||||||||||||||||||||||||||||||||||||||||
| Fracture | Conchoidal, Gems, Sixth Edition (2006) More from other references | |||||||||||||||||||||||||||||||||||||||||||||
| Refractive Index | 1.544 to 1.553, Gemmological Tables (2004) More from other references | |||||||||||||||||||||||||||||||||||||||||||||
| Optical Character | Uniaxial/+, Gemmological Tables (2004) | |||||||||||||||||||||||||||||||||||||||||||||
| Birefringence | 0.009, Gemmological Tables (2004) More from other references | |||||||||||||||||||||||||||||||||||||||||||||
| Pleochroism | Weakly dichroic, Gemstones (2009) | |||||||||||||||||||||||||||||||||||||||||||||
| Dispersion |
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