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Gemstones, Minerals & Fossils
Gemstones and Minerals
❓Your Mineral Identification Questions answered here
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<blockquote data-quote="user 4386" data-source="post: 503714" data-attributes="member: 4386"><p>Looks a bit like spinel - SG would help determine, also it will scratch quartz (almost as hard as topaz). </p><p></p><p>Can occur with ruby in some areas but not others - if derived from igneous rocks they often occur together (if the magmas are relatively deficient in sodium and potassium relative to aluminium, aluminium oxide may form as the mineral corundum = ruby and sapphire, or may combine with magnesium to form spinel). However often they are simply brought from depth in the magma. However these things are more true of sapphire, as in eastern Australia, where rubies are very sparse - many important ruby fields of the world instead occur in limestone.</p></blockquote><p></p>
[QUOTE="user 4386, post: 503714, member: 4386"] Looks a bit like spinel - SG would help determine, also it will scratch quartz (almost as hard as topaz). Can occur with ruby in some areas but not others - if derived from igneous rocks they often occur together (if the magmas are relatively deficient in sodium and potassium relative to aluminium, aluminium oxide may form as the mineral corundum = ruby and sapphire, or may combine with magnesium to form spinel). However often they are simply brought from depth in the magma. However these things are more true of sapphire, as in eastern Australia, where rubies are very sparse - many important ruby fields of the world instead occur in limestone. [/QUOTE]
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Gemstones, Minerals & Fossils
Gemstones and Minerals
❓Your Mineral Identification Questions answered here
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