Microcline
Amazonite
Brazil
2.93 carats
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The blue-green feldspar amazonite is the only gem variety of microcline.
Microcline 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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Microcline Gemstones by Size
This table shows distribution of Microcline 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:0.31 cts
Heaviest:33.86 cts
Average:10.59 cts
Total photos:28
Do you have a larger Microcline? Why not upload a photo?
| General Information | |||||||||||||||||||||||||
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| A variety or type of: | Feldspar | ||||||||||||||||||||||||
| Varieties/Types: | Amazonite - A green to blue-green variety of Microcline. | ||||||||||||||||||||||||
| Chemical Formula |
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| Physical Properties of Microcline | |||||||||||||||||||||||||
| Mohs Hardness | 6 to 6.5, Gems, Sixth Edition (2006) More from other references | ||||||||||||||||||||||||
| Specific Gravity | 2.55 to 2.63, Gems, Sixth Edition (2006) More from other references | ||||||||||||||||||||||||
| Cleavage Quality | Perfect, Gems, Sixth Edition (2006) | ||||||||||||||||||||||||
| Fracture | Uneven,Conchoidal, Gems, Sixth Edition (2006) More from other references | ||||||||||||||||||||||||
| Optical Properties of Microcline | |||||||||||||||||||||||||
| Refractive Index | 1.514 to 1.539, Gems, Sixth Edition (2006) Alpha 1.514–1.529; beta 1.518–1.533; gamma 1.521–1.539More from other references | ||||||||||||||||||||||||
| Optical Character | Biaxial/-, Gems, Sixth Edition (2006) More from other references | ||||||||||||||||||||||||
| Birefringence | 0.008 to 0.010, Gems, Sixth Edition (2006) More from other references | ||||||||||||||||||||||||
| Pleochroism | Weak, Gems, Sixth Edition (2006) More from other references | ||||||||||||||||||||||||
| Dispersion | Weak, Gems, Sixth Edition (2006) More from other references | ||||||||||||||||||||||||
| Colour | |||||||||||||||||||||||||
| Colour (General) | Commonly white to pale yellow or salmon, also may be blue to green, Gems, Sixth Edition (2006) More from other references | ||||||||||||||||||||||||
| Causes of Colour | Blue (amazonite), color center involving Pb3+ and structural water, Pragmatic Spectroscopy For Gemologists (2011) | ||||||||||||||||||||||||
| Transparency | Translucent,Opaque, Gems, Sixth Edition (2006) Rarely transparentMore from other references | ||||||||||||||||||||||||
| Lustre | Vitreous, Gems, Sixth Edition (2006) More from other references | ||||||||||||||||||||||||
| Fluorescence & other light emissions | |||||||||||||||||||||||||
| Fluorescence (Short Wave UV) | May fluoresce with a weak red or moderate blue colour, bluish white or pale greyish green. Microcline from Franklin, New Jersey, is reported as having a medium blue–grey fluorescence., Gems, Sixth Edition (2006) | ||||||||||||||||||||||||
| Crystallography of Microcline | |||||||||||||||||||||||||
| Crystal System | Triclinic, Gems, Sixth Edition (2006) More from other references | ||||||||||||||||||||||||
| Habit | Prismatic, Gemstones (2009) | ||||||||||||||||||||||||
| Geological Environment | |||||||||||||||||||||||||
| Where found: | Microcline commonly occurs in plutonic igneous rocks such as granites and syenites that cooled slowly and at considerable depth., Gems, Sixth Edition (2006) | ||||||||||||||||||||||||
| Further Information | |||||||||||||||||||||||||
| Mineral information: | Microcline information at mindat.org | ||||||||||||||||||||||||
| Significant Gem Localities | |||||||||||||||||||||||||
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