Topic: geology et al
Sulfides are complex and valuable. Scientific understanding of their origins is incomplete. Sulfides are deposited in cracks in the earth's crust. Igneous rock (usually granite) forms the core of folded mountain ranges. It has been formed from crystallizing magma, the hot stuff that forms the earth's core. As the magma cools, its minerals form, starting with iron, magnesium, calcium silicates, and so on. The last one to form is quartz. As the granite formation cools, cracks form. Hot water left over from the process moves through the cracks and elements precipitate out, with metals and semi metals combining with sulfur and forming veins. As the less soluble elements crystallize at higher temperatures, those are found near the source and more soluble elements are found further away. These deposits are called hydrothermal veins. It is not so easy to understand the crystallization sequence.
Some of these sulfur compounds are realgar, orpiment, cinnabar and greenockite. To my knowledge I don't have any of these in my collection.
I am finishing up my confession story today. It's sort of funny...humorous type funny I mean. At least I hope it is.
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