Obsidian is a natural colored glass formed by the sudden cooling of magma from volcanic lava. It is an amorphous gem, and its main component is silicon dioxide (SiO2).
In the process of formation, because the temperature around the lava flow drops rapidly and the cooling rate is the fastest, the magma containing silicon dioxide quickly condenses into blocks, and obsidian generally appears around the lava flow or near the seaside at the foot of the volcano. Because of its unique formation process, the crystal of obsidian also contains 1%-2% water.
Obsidian can be processed into handicrafts. In addition, obsidian has the characteristics of glass, and its cross section is shell-shaped and very sharp. In the ancient stone age, it was used as cutting tools such as knives and arrows. Modern people use obsidian as a scalpel blade for surgery. When obsidian is heated above 65,438+0,000℃, it will become white particles with loose and porous texture due to the loss of water contained in it.
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Distribution of obsidian origin
Obsidian is mostly distributed in areas with volcanic activity, such as Hawaii, Japan and Java Island in the United States, as well as Iceland, Hungary, Lipari Islands in Italy, the former Soviet Union, Mexico, Ecuador and Guatemala, and Tibet in China.
Dark black monocular obsidian is distributed in Arizona and New Mexico, and Indians call it "Apache tears".
Most obsidian jewelry is produced in Central America and North America and is the national stone of the United Mexican States.
Baidu Encyclopedia-Obsidian