Hot atmospheres could have iron rain, molten-glass rain, and rain made from rocky minerals such as enstatite, corundum, spinel, and wollastonite.
en.wikipedia.org Minerals that often display parting include the pyroxenes, hematite, magnetite, and corundum.
en.wikipedia.org The typical asteria is the star-sapphire, generally a bluish-grey corundum, milky or opalescent, with a star of six rays.
en.wikipedia.org For example, ruby is the red variety of the species corundum, while any other color of corundum is considered sapphire.
en.wikipedia.org It occurs with calcite, ettringite, wollastonite, larnite, brownmillerite, gehlenite, diopside, pyrrhotite, grossular, spinel, afwillite, jennite, portlandite, jasmundite, melilite, kalsilite and corundum in the limestone xenoliths.
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