Sphalerite
Spain
17.78 carats
© Mineral Classics
Sphalerite forms clear crystals with colours ranging from pale yellow to orange and red shades, with the presence of iron it forms dark, opaque metallic crystals.
Gem-quality material often has yellowish to honey brown, red to orange, or green colour. The brilliant cut best displays sphalerite's high dispersion of 0.156 (three times as high as for diamond). Because of its softness and fragility sphalerite gems are usually used as collector's pieces and sometomes set into pendants.
Sphalerite 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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Sphalerite Gemstones by Size
This table shows distribution of Sphalerite 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:0.54 cts
Heaviest:351.52 cts
Average:21.74 cts
Total photos:71
Do you have a larger Sphalerite? Why not upload a photo?
| General Information | ||||||||||||||||||||||
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| Chemical Formula |
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| Synthetic Sphalerite | ||||||||||||||||||||||
| Synthetic sphalerite - ZnS; Isometric; Colourless, green, yellow; Transparent; Hardness 3-4; RI 2.25 - 2.35; Opt. isotropic; SG 4.03 - 4.09 - Gemmological Tables, Ulrich Henn and Claudio C. Milisenda, 2004, p 30 | ||||||||||||||||||||||
| Physical Properties of Sphalerite | ||||||||||||||||||||||
| Mohs Hardness | 3.5 to 4, Blue Chart Gem Identification (2010) More from other references | |||||||||||||||||||||
| Specific Gravity | 3.95 to 4.10, Blue Chart Gem Identification (2010) More from other references | |||||||||||||||||||||
| Tenacity | Brittle, Gemstones of the world (2001) | |||||||||||||||||||||
| Cleavage Quality | Perfect, Blue Chart Gem Identification (2010) More from other references | |||||||||||||||||||||
| Fracture | Uneven, Gemstones of the world (2001) More from other references | |||||||||||||||||||||
| Optical Properties of Sphalerite | ||||||||||||||||||||||
| Refractive Index | 2.368 to 2.371, Blue Chart Gem Identification (2010) More from other references | |||||||||||||||||||||
| Optical Character | Isotropic, Gemmological Tables (2004) More from other references | |||||||||||||||||||||
| Birefringence | None, Gemstones of the world (2001) | |||||||||||||||||||||
| Pleochroism | Absent, Gemstones of the world (2001) | |||||||||||||||||||||
| Dispersion | Very strong, Blue Chart Gem Identification (2010) More from other references | |||||||||||||||||||||
| Chatoyancy | Yes, Blue Chart Gem Identification (2010) | |||||||||||||||||||||
| Colour | ||||||||||||||||||||||
| Colour (General) | Opaque: black, gray-brown, cinnamon-colour. Translucent to transparent: yellow, yellow-green, green, red-yellow, yellowish-brown, Gemmological Tables (2004) More from other references | |||||||||||||||||||||
| Causes of Colour | Yellow to black, iron → sulfur charge transfer. Green, Co2+ in tetrahedral coordination, Pragmatic Spectroscopy For Gemologists (2011) | |||||||||||||||||||||
| Transparency | Transparent,Translucent,Opaque, Gemmological Tables (2004) More from other references | |||||||||||||||||||||
| Lustre | Adamantine,Greasy, Gemstones of the world (2001) More from other references | |||||||||||||||||||||
| Fluorescence & other light emissions | ||||||||||||||||||||||
| Fluorescence (General) | Inert to strong orangy red, Blue Chart Gem Identification (2010) More from other references | |||||||||||||||||||||
| Crystallography of Sphalerite | ||||||||||||||||||||||
| Crystal System | Isometric, Blue Chart Gem Identification (2010) More from other references | |||||||||||||||||||||
| Habit | Tetrahedral, dodecahedral, Gems, Sixth Edition (2006) More from other references | |||||||||||||||||||||
| Geological Environment | ||||||||||||||||||||||
| Where found: | Sphalerite occurs in a variety of hydrothermal conditions and is the chief ore of zinc., Gems, Sixth Edition (2006) | |||||||||||||||||||||
| Further Information | ||||||||||||||||||||||
| Mineral information: | Sphalerite information at mindat.org | |||||||||||||||||||||
| Significant Gem Localities | ||||||||||||||||||||||
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