Rock Crystal
Crystalline Quartz Dreamscape Cut
16.93 carats
© johndyergems.com
The name Crystal comes from the Greek for "ice", as it was believed that Rock Crystal was eternally frozen. Rock Crystals weighing many tons have been found. Cuttable material is rare.
Rock Crystal is used for costume jewelry and delicate bowls and to imitate diamonds.
Rock Crystal 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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Rock Crystal Gemstones by Size
This table shows distribution of Rock Crystal 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:7.62 cts
Heaviest:72.07 cts
Average:29.82 cts
Total photos:11
Do you have a larger Rock Crystal? Why not upload a photo?
| General Information | |||||||||||||||||||||
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| A variety or type of: | Quartz | ||||||||||||||||||||
| Chemical Formula |
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| Rock Crystal Treatments | |||||||||||||||||||||
| Cracks are induced (heating and quick cooling) then dyed in any color, magnification: web-like network. Iris, rainbow quartz have iridescence due to cracks. Coated (all colors) with ultra-thin layer of metallic elements (gold for light blue "Aquaaura"), color concentration along facet junctions or irregular distribution, peeled coating. Sharp blade, acetone, acid tests - Blue Chart Gem Identification, Herve Nicolas Lazzarelli, 2010, p 7 | |||||||||||||||||||||
| Rock Crystal Simulants | |||||||||||||||||||||
| Imitations made of quartz triplets are common - Blue Chart Gem Identification, Herve Nicolas Lazzarelli, 2010, p 7 | |||||||||||||||||||||
| Synthetic Rock Crystal | |||||||||||||||||||||
| Synthetic rock crystal is used only for industrial purposes. - Gemstones of the world, Walter Schumann, 2001, p 116 | |||||||||||||||||||||
| Physical Properties of Rock Crystal | |||||||||||||||||||||
| Mohs Hardness | 7, Blue Chart Gem Identification (2010) | ||||||||||||||||||||
| Specific Gravity | 2.65, Gemstones of the world (2001) More from other references | ||||||||||||||||||||
| Tenacity | Brittle, Gemstones of the world (2001) Very brittle | ||||||||||||||||||||
| Cleavage Quality | None, Gemstones of the world (2001) | ||||||||||||||||||||
| Fracture | Conchoidal, Gemstones of the world (2001) | ||||||||||||||||||||
| Optical Properties of Rock Crystal | |||||||||||||||||||||
| Refractive Index | 1.544 to 1.553, Blue Chart Gem Identification (2010) | ||||||||||||||||||||
| Optical Character | Uniaxial/+, Blue Chart Gem Identification (2010) | ||||||||||||||||||||
| Birefringence | 0.009, Blue Chart Gem Identification (2010) | ||||||||||||||||||||
| Pleochroism | Absent, Gemstones of the world (2001) | ||||||||||||||||||||
| Dispersion | 0.013, Gemstones of the world (2001) | ||||||||||||||||||||
| Chatoyancy | Star 4/6/12 (rare), Blue Chart Gem Identification (2010) | ||||||||||||||||||||
| Colour | |||||||||||||||||||||
| Colour (General) | Colorless, Blue Chart Gem Identification (2010) More from other references | ||||||||||||||||||||
| Transparency | Transparent, Gemstones of the world (2001) More from other references | ||||||||||||||||||||
| Lustre | Vitreous, Gemstones of the world (2001) | ||||||||||||||||||||
| Fluorescence & other light emissions | |||||||||||||||||||||
| Fluorescence (General) | None, Gemstones of the world (2001) | ||||||||||||||||||||
| Crystallography of Rock Crystal | |||||||||||||||||||||
| Crystal System | Trigonal, Blue Chart Gem Identification (2010) | ||||||||||||||||||||
| Habit | Hexagonal prisms, Gemstones of the world (2001) | ||||||||||||||||||||
| Geological Environment | |||||||||||||||||||||
| Where found: | Rock crystal is found widespread in the world., Gems, Sixth Edition (2006) | ||||||||||||||||||||
| Inclusions in Rock Crystal | |||||||||||||||||||||
| Huge variety of inclusions such as 2 phase inclusions, golden rutile needles ("Venus hair"), black tourmaline crystals, fibers of green actinolite, mossy-like green chlorite, dark red hematite - Blue Chart Gem Identification, Herve Nicolas Lazzarelli, 2010, p 7 | |||||||||||||||||||||
| Further Information | |||||||||||||||||||||
| Mineral information: | Rock Crystal information at mindat.org | ||||||||||||||||||||
| Significant Gem Localities | |||||||||||||||||||||
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