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Helenite, also known as Mount St. Helens obsidian, emerald obsidianite, and ruby obsidianite, is a glass made from the fused volcanic rock dust from Mount St. Helens and marketed as a gemstone. [ 1 ] [ 2 ] Helenite was first created accidentally after the eruption of Mount St. Helens in 1980 .
Knapping is the shaping of flint, chert, obsidian, or other conchoidal fracturing stone through the process of lithic reduction to manufacture stone tools, strikers for flintlock firearms, or to produce flat-faced stones for building or facing walls, and flushwork decoration.
Obsidian hydration dating (OHD) is a geochemical method of determining age in either absolute or relative terms of an artifact made of obsidian.. Obsidian is a volcanic glass that was used by prehistoric people as a raw material in the manufacture of stone tools such as projectile points, knives, or other cutting tools through knapping, or breaking off pieces in a controlled manner, such as ...
The analysis of obsidian debitage can reveal whether or not prismatic blade production occurred at a site and, if it had, what stages of production the process included. In other words, the types of manufacturing waste present (e.g., rejuvenation flakes and/or blades, platform rejuvenation flakes, etc.) at a site can inform archaeologists about ...
Despite being sharper, prismatic obsidian is also considerably more brittle than steel; obsidian blades of the type used on the macuahuitl tended to shatter on impact with other obsidian blades, steel swords or plate armour. Obsidian blades also have difficulty penetrating European mail. The thin, replaceable blades used on the macuahuitl were ...
Obsidian projectile point.. Obsidian is a naturally formed volcanic glass that was an important part of the material culture of Pre-Columbian Mesoamerica.Obsidian was a highly integrated part of daily and ritual life, and its widespread and varied use may be a significant contributor to Mesoamerica's lack of metallurgy.
In metallurgy, refining consists of purifying an impure metal. It is to be distinguished from other processes such as smelting and calcining in that those two involve a chemical change to the raw material, whereas in refining the final material is chemically identical to the raw material.
Mineral dust is mainly constituted of the oxides (SiO 2, Al 2 O 3, FeO, Fe 2 O 3, CaO, and others) and carbonates (CaCO 3, MgCO 3) that constitute the Earth's crust.The composition of mineral dust, usually named in atmospheric sciences as mineralogy composition, is relevant for different physical and chemical processes in the atmosphere, for example, oxides with iron have an effect in the ...