Tourmaline Crystals- 5.08 g
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Description from the seller
25カラットのファセットが施された粗石トルマリン
Origin kunar Afghanistan
Untreated and unheated
Faceted rough quality
Open colour
Good clarity (eye clean pieces)
Characteristic of Tourmaline
Chemical composition: Complex borosilicate of aluminium with varying amounts of iron, magnesium, lithium, sodium, calcium, and other elements
Crystal system: Trigonal
Hardness: 7–7.5 on the Mohs scale
Specific gravity: 3.00–3.26
Refractive index: 1.614–1.666
Birefringence: 0.014–0.040
Luster: Vitreous
Transparency: Transparent to opaque
Cleavage: Indistinct to poor
Fracture: Uneven to subconchoidal
Dispersion: 0.017–0.020
Pleochroism: Strong, especially in colored varieties
Common colors: Colorless, pink, red, green, blue, yellow, brown, black, violet, and multicolored (bicolor and watermelon)
Fluorescence: Usually inert, though some pink and red tourmalines may show weak fluorescence
Inclusions: Hollow tubes, liquid inclusions, growth tubes, fingerprints, healed fractures, and mineral crystals
Common treatments: Heat treatment is common; irradiation is less common
Major sources: Pakistan, Afghanistan, Brazil, Nigeria, Mozambique, Madagascar, Namibia, Sri Lanka, Tanzania, and the United States
25カラットのファセットが施された粗石トルマリン
Origin kunar Afghanistan
Untreated and unheated
Faceted rough quality
Open colour
Good clarity (eye clean pieces)
Characteristic of Tourmaline
Chemical composition: Complex borosilicate of aluminium with varying amounts of iron, magnesium, lithium, sodium, calcium, and other elements
Crystal system: Trigonal
Hardness: 7–7.5 on the Mohs scale
Specific gravity: 3.00–3.26
Refractive index: 1.614–1.666
Birefringence: 0.014–0.040
Luster: Vitreous
Transparency: Transparent to opaque
Cleavage: Indistinct to poor
Fracture: Uneven to subconchoidal
Dispersion: 0.017–0.020
Pleochroism: Strong, especially in colored varieties
Common colors: Colorless, pink, red, green, blue, yellow, brown, black, violet, and multicolored (bicolor and watermelon)
Fluorescence: Usually inert, though some pink and red tourmalines may show weak fluorescence
Inclusions: Hollow tubes, liquid inclusions, growth tubes, fingerprints, healed fractures, and mineral crystals
Common treatments: Heat treatment is common; irradiation is less common
Major sources: Pakistan, Afghanistan, Brazil, Nigeria, Mozambique, Madagascar, Namibia, Sri Lanka, Tanzania, and the United States
Details
主要鉱物
Tourmaline
鉱物形態
Crystals
重量
5.08 g
産地 (地域/都市)
Kunar
原産国
Afghanistan
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