| General Information |
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| A variety or type of: | Anorthite, which is a variety of Feldspar |
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| Other Names/Trade Names: | Spectrolite - Trade name for a Labradorite from Finland that shows the spectral colours especially effectively. |
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| Chemical Formula | | Na(30-50%)Ca(70-50%)(Al,Si)AlSi | | O | | |
Michael O’Donoghue, Gems, Sixth Edition (2006) |
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| Physical Properties of Labradorite |
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| Mohs Hardness | 6 to 6.5Herve Nicolas Lazzarelli, Blue Chart Gem Identification (2010) More from other references |
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| Specific Gravity | 2.69 to 2.72Herve Nicolas Lazzarelli, Blue Chart Gem Identification (2010) More from other references |
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| Tenacity | BrittleMichael O’Donoghue, Gems, Sixth Edition (2006) |
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| Cleavage Quality | PerfectUlrich Henn and Claudio C. Milisenda, Gemmological Tables (2004) More from other references |
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| Fracture | UnevenMichael O’Donoghue, Gems, Sixth Edition (2006) |
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| Refractive Index | 1.554 to 1.573Herve Nicolas Lazzarelli, Blue Chart Gem Identification (2010) More from other references |
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| Optical Character | Biaxial/+Herve Nicolas Lazzarelli, Blue Chart Gem Identification (2010) More from other references |
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| Birefringence | 0.007 to 0.011Herve Nicolas Lazzarelli, Blue Chart Gem Identification (2010) More from other references |
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| Pleochroism | From the Congo, red stones show weak pleochroism whilst greenstones have distinct greenish yellow to bluish green pleochroismMichael O’Donoghue, Gems, Sixth Edition (2006) |
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| Dispersion |
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| Call Stack |
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| # | Time | Memory | Function | Location |
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| 1 | 0.0007 | 360344 | {main}( ) | .../gshow.php:0 |
| 2 | 0.4397 | 840296 | gemshow_class->do_optical( ) | .../gshow.php:151 |
| 3 | 0.4539 | 856824 | gemshow_class->showblock( $txt = 'DISPERS-MIN' ) | .../gemshow_class.php:1469 |
| 4 | 0.4540 | 873960 | gemshow_class->showdata( $dataname = 'DISPERS-MIN' ) | .../gemshow_class.php:505 |
| 5 | 0.4540 | 874440 | query( $query = 'select * from mineralproperties,mineralpropertytypes where \r\n\t\t\t\t\tmp_mpt_id=mpt_id and mpt_code=\'DISPERS-MAX\' and \r\n\t\t\t\t\tmp_min_id=\'2308\' and mp_deleted=0 and\r\n\t\t\t\t\tmp_reference=\'Gems, Sixth Edition\' and\r\n\t\t\t\t\tmp_referenceauthor=\'Michael O’Donoghue\' and\r\n\t\t\t\t\tmp_referenceyear=\'2006\' and\r\n\t\t\t\t\tmp_referencepublisher=\'Elsevier\' and\r\n\t\t\t\t\tmp_referenceperiodical=\'\'' ) | .../gemshow_class.php:690 |
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