Gahnite - Wikipedia
Gahnite, ZnAl 2 O 4, is a rare mineral belonging to the spinel group. It forms octahedral crystals which may be green, blue, yellow, brown or grey. It often forms as an alteration product of sphalerite in altered massive sulphide deposits such as at Broken Hill, Australia.
Gahnite: Mineral information, data and localities. - mindat.org
Formula: ZnAl2O4. Colour: Dark blue-green, yellow, brown, black. Lustre: Vitreous. Hardness: 7½ - 8. Specific Gravity: 4.62 (Calculated) Crystal System: Isometric. Member of: Spinel Subgroup > Oxyspinel Group > Spinel Supergroup.
Gahnite
Gahnite is a rare zinc-bearing member of the Spinel Group that was named in 1807, but the species has been known prior to its naming. This thumbnail specimen is a rarely seen example from Broken Hill in New South Wales, Australia.
Gahnite : Properties, Formation, Uses, Locations - Geology Science
2024年5月9日 · Gahnite is a mineral belonging to the spinel group, specifically a zinc aluminum oxide with the chemical formula ZnAl2O4ZnAl_2O_4ZnAl2 O4 . It is typically found in metamorphic and pegmatitic rocks and is known for its characteristic dark green, blue-green, or blue-black color, which can vary depending on its composition.
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Gahnite ZnAl2O4
Gahnite ZnAl2O4. Crystal Data: Cubic. Point Group: 4/m32/m. Typically octahedra, rarely as dodecahedra, may be modified by {100} or {011}, to 12 cm; also as exsolution lamellae in other minerals; granular, massive.
Gahnite Mineral Data
Gahnite. Comments: Deep blue octahedral crystals of gahnite in quartz. Location: Franklin, Sussex County, New Jersey, USA. Scale: See Photo. © Jeff Weissman / Photographic Guide to Mineral Species. Images: Gahnite.
Gahnite - an overview | ScienceDirect Topics
Gahnite is defined as a dark grey mineral with a chemical composition of ZnAl2O4, commonly found in granites, metamorphic rocks, and base-metal sulfide deposits. It typically occurs in large octahedral crystals and has an average hardness of 7.75.
Blue Gahnite from Nigeria | Gems & Gemology
2019年5月15日 · The spinels from Kagoro have been identified as gahnite, the zinc end member. Gahnite is one of the rarer members of the spinel group of minerals, typically found at zinc deposits. Most crystals are very small, included, and translucent to opaque.
Gahnite | mineral | Britannica
Gahnite, the mineral zinc aluminum oxide, a member of the spinel (q.v.)
Gahnite - Wikiwand
Gahnite, ZnAl2O4, is a rare mineral belonging to the spinel group. It forms octahedral crystals which may be green, blue, yellow, brown or grey. It often forms as an alteration product of sphalerite in altered massive sulphide deposits such as at Broken Hill, Australia.
Mineral chemistry of gahnite from the Lalor ... - GeoScienceWorld
2020年7月1日 · Gahnite (ZnAl 2 O 4) is a common accessory mineral at the Lalor auriferous Zn-Cu metamorphosed VHMS deposit (Snow Lake, Manitoba). To evaluate factors influencing its crystal chemistry, gahnite representing a range of textures, host mineral assemblages, and whole-rock compositions were analyzed for major, minor, and trace elements.
Gahnite – WGNHS – UW–Madison
Gahnite is an uncommon mineral found in schists and high temperature hydrothermal deposits. DODGE COUNTY: Tiny aggregates of octahedral xls. were seen in pegmatites cutting quartzite in the Michels Materials Waterloo Quarry, NE sec. 33 and NW sec. 34 T.9N. R.13E.
Structural Study of Nano-Sized Gahnite (ZnAl2O4): From the …
Gahnite is a spinel with a chemical formula ZnAl 2 O 4, crystallizing in the Fd3 ¯¯¯m space group. The unit cell presents 32 oxygen atoms, which comprise 8 tetrahedral sites, usually occupied by the divalent cations, and 16 octahedral sites where the trivalent cation is positioned (see for example [ 1] and the references therein).
Gahnite composition: Implications for base metal and rare …
1997年7月1日 · Gahnite, a zinc-bearing spinel, is a resistate mineral that may be used as an indicator mineral of polymetallic deposits in high-grade metamorphic terrain. The Ontario Geological Survey recently...
The mineral chemistry of gahnite, garnet and columbite-group …
2020年2月1日 · Gahnite (ZnAl 2 O 4), a member of the spinel group minerals, is represented by the general formula AB 2 O 4. The A and B site is occupied by Zn and Al respectively, but these elements can be replaced by Li, Rb, Ba, Ga, Cu, Ti, and Sn (Hensen, 1967; Knorring and Dearnley, 1960).
Gahnite composition; implications for base metal and rare …
Gahnite composition; implications for base metal and rare-element exploration. T. F. Morris; F. W. Breaks; S. A. Averill; D. C. Crabtree; A. McDonald. Author and Article Information. Exploration and Mining Geology (1997) 6 (3): 253–260. Article history.
Gahnite - Geology Page
2014年3月27日 · Gahnite, ZnAl 2 O 4, is a rare mineral belonging to the spinel group. It forms octahedral crystals which may be green, blue, yellow, brown or grey. It often forms as an alteration product of sphalerite in altered massive sulphide …
Gahnite, chrysoberyl and beryl co-occurrence as accessory …
2013年10月1日 · Introduction. The co-occurrence of gahnite (Zn-rich hercynite), chrysoberyl and beryl is uncommon in igneous rocks. This mineral association has only been described in Na-metasomatized pegmatites (Alfonso and Melgarejo, 2008), but chrysoberyl was interpreted as a secondary product of beryl replacement.
A “Cobalt Blue” Gahnospinel - GIA
2019年5月15日 · Interestingly, gahnospinel is usually found with a more muted dark blue to dark greenish blue color, but this intense blue specimen contained cobalt as the primary coloring agent, similar to “cobalt blue” gem spinel.
Gahnite Definition & Meaning - Merriam-Webster
The meaning of GAHNITE is a usually dark green mineral consisting of an oxide of zinc and aluminum.