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AGATE
Oct 13, 2022 10:05:30 GMT -7
Post by Admin on Oct 13, 2022 10:05:30 GMT -7
Agate forms at low to moderate temperatures in voids. en.wikipedia.org/wiki/AgateOLYMPUS DIGITAL CAMERA - Doxymo - Own work Botswana agate - Pschemp Hollow agate James St. John - Agate- & quartz-lined geode 5 I think the debris filled sphere was the original bottom, obviously a gas bubble in andesite. Coyamito Agates From México - Agatesfm - Own work How is agate formed?
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AGATE
Oct 13, 2022 10:06:12 GMT -7
Post by Admin on Oct 13, 2022 10:06:12 GMT -7
Even the experts are perplexed! Agate in steam bubbles from basalt and andesite provide a lot of information. Add to that the agate that formed in steam ruptured crystobalite spheres known as lithophasae or thundereggs and the sequences become obvious, BUT what is the process? #1 Problem. transportation into the voids is obviously accomplished by groundwater. The least common dissolved mineral substances in groundwater are the silicates. The most common dissolved mineral substances in groundwater are the limestones and carbonates, specifically ions of sodium, calcium, magnesium, potassium; iron and manganese; chloride, bicarbonate, and sulfate. In water chemistry, these substances are called common constituents. But Agate is mostly SiO2, the least soluble! chemrxiv.org/engage/api-gateway/chemrxiv/assets/orp/resource/item/60c741aaf96a00fda52864a5/original/agate-analysis-by-raman-xrf-and-hyperspectral-imaging-spectroscopy-for-provenance-determination.pdf"Agate from the Idar-Oberstein is Permian in age (around 280 million years old). Agate from Rio Grande do Sul of Brazil generally formed during the Cretaceous (around 120 million years old)." Interesting, but is it accurate? That is when the gas bubbles formed, but not when they filled. In my opinion, agates are mostly chalcedony fibers with agate tips and scattered opal spheres.
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