pyrope
Sign in to savethumb|Pyrope garnet in eclogite - Shibino, Ural Mountains, Russia. The mineral pyrope is a member of the garnet group. Pyrope is the only member of the garnet family to always display red colouration in natural samples, and it is from this characteristic that it gets its name: from the Greek words for fire and eye. Despite being less common than most garnets, it is a widely used gemstone with numerous alternative names, some of which are misnomers. Chrome pyrope, and Bohemian garnet are two alternative names, the usage of the latter being discouraged by the Gemological Institute of America. Mi
Key facts
- Mineral.name
- Pyrope
- Mineral.category
- Nesosilicate
- Mineral.boxtextcolor
- FFFFFF
- Mineral.boxbgcolor
- 270000
- Mineral.image
- Pyrope-260132.jpg
- Mineral.strunz
- 9.AD.25
- Mineral.formula
- Mg3Al2(SiO4)3
- Mineral.IMAsymbol
- Prp
- Mineral.system
- Cubic
- Mineral.class
- Hexoctahedral (mm) H–M symbol: (4/m 2/m)
- Mineral.symmetry
- Iad
- Mineral.color
- Blood red to black red, red, orange red, pink, some varieties are very dark, almost black, while others can take tones of purple to purple red, Some chromium-rich pyropes are thermochromic, becoming green when heated.
- Mineral.habit
- Euhedra typically display rhombic dodecahedral form, but trapezohedra are not uncommon, and hexoctahedra are seen in some rare samples. Massive and granular forms also occur.
- Mineral.cleavage
- None
- Mineral.fracture
- Conchoidal
- Mineral.mohs
- 7.0–7.5
- Mineral.luster
- greasy to vitreous
- Mineral.polish
- vitreous
via Wikipedia infobox
Article
4 sectionsContents
- Composition
- Distribution
- Mineral identification
- References
thumb|Pyrope garnet in eclogite - Shibino, Ural Mountains, Russia. The mineral pyrope is a member of the garnet group. Pyrope is the only member of the garnet family to always display red colouration in natural samples, and it is from this characteristic that it gets its name: from the Greek words for fire and eye. Despite being less common than most garnets, it is a widely used gemstone with numerous alternative names, some of which are misnomers. Chrome pyrope, and Bohemian garnet are two alternative names, the usage of the latter being discouraged by the Gemological Institute of America. Misnomers include Colorado ruby, Arizona ruby, California ruby, Rocky Mountain ruby, Elie Ruby, Bohemian carbuncle, and Cape ruby.
== Composition == The composition of pure pyrope is Mg3Al2(SiO4)3, although typically other elements are present in at least minor proportions—these other elements include Ca, Cr, Fe and Mn. Pyrope forms a solid solution series with almandine and spessartine, which are collectively known as the pyralspite garnets (pyrope, almandine, spessartine). Iron and manganese substitute for the magnesium in the pyrope structure. The resultant, mixed composition garnets are defined according to their pyrope-almandine ratio. The semi-precious stone rhodolite is a garnet of ~70% pyrope composition.