hercynite


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hercynite

[′hərs·ən‚īt]
(mineralogy)
(Fe,Mg)Al2O4 A black mineral of the spinel group; crystallizes in the isometric system. Also known as ferrospinel; iron spinel.
References in periodicals archive ?
Sharp black octahedral crystals of the iron-rich spinel hercynite and small grains of what may be diopside have been found loose in the thin alpine soil along the west slope of Green Monster's summit plateau some 40 meters southwest of the clintonite site.
Even though hercynite is a comparatively rare mineral in granulites, not its presence but its form merits a special attention in the case of the rock examined.
Hercynite grains of the symplectite, mostly hundredths of mm in site, are isometric and almost xenoblastic.
Rather it was more likely due to a metal oxide system as that of iron, possibly including other spinels such as hercynite, in which the changes between the various coloring agents (for example, red hematite contrasted with black magnetite, or maghemite, or wustite, or some combination thereof) are reversible.
In spinel-forming refractories that are alumina-enriched, it is possible to form either hercynite or galaxite [ILLUSTRATION FOR FIGURE 3 OMITTED].
Penetration of FeO resulted in formation of hercynite (FeO*[Al.
For example, aluminum-coated or killed steel used in cast iron melting will result in alumina or alumina complex mineral deposits such as hercynite (iron aluminate), mullite (silica alumina), etc.
PHOTO : CL micrograph of a buildup sample showing anorthite (yellow), corundum (red) and hercynite (black) crystals.