Non-crystaline Minerals

Obsidian

Sometimes the magna expelled from a volcano cools so quickly that crystals are not able to form. If the magna is rich in silica it forms a type of glass called obsidian.

Chemically, obsidian is very similar to the igneous rocks, granite and rhyolite. If the magna cools slowly, deep within the Earth, it forms large crystals of granite. If it cools more quickly, near or on the Earth's surface, it forms smaller crystals of rhyolite.

 

Tektites

Tektites are lumps of glass, usually small, which are associated with meteorite impacts. They may be shaped like tears, rods, disks, buttons or dumb-bells. They may be black, brown or green.

Tektites may be either the remains of meteorites or they may be formed when meteorites hit the Earth. The collision causes molten rock to be ejected into the air. The molten rock cools quickly to form small glass beads.

Tektite

 


 

Non-crystaline specimens now available (at eBay):

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APACHE TEAR on PERLITE - Arizona, United States - Obsidian 3.1x3x2.5cm NICE!

AU $9.20
End Date: Monday Jul-6-2020 16:06:45 EST
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APACHE TEAR on PERLITE - Arizona, United States - Obsidian 2.8x2.6x2.4cm NICE!

AU $9.20
End Date: Monday Jul-6-2020 16:02:23 EST
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2 Rainbow Obsidian 8 Mm Bracelets

AU $40.00
End Date: Wednesday Jul-1-2020 14:27:29 EST
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Obsidian Mirror for scrying ~ 4.8cm

AU $10.00
End Date: Monday Jul-6-2020 18:00:36 EST
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APACHE TEAR on PERLITE - Arizona, United States - Obsidian 3x2x2cm NICE!

AU $9.20
End Date: Friday Jul-3-2020 15:02:09 EST
Buy It Now for only: AU $9.20
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APACHE TEAR on PERLITE - Arizona, United States - Obsidian 3x2.8x2.1cm NICE!

AU $9.20
End Date: Friday Jul-3-2020 14:59:21 EST
Buy It Now for only: AU $9.20
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