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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.
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 ...
In some stones, the inclusion of small, white, radially clustered crystals (spherulites) of the mineral cristobalite in the black glass produce a blotchy or snowflake pattern (snowflake obsidian). Obsidian may contain patterns of gas bubbles remaining from the lava flow, aligned along layers created as the molten rock was flowing before being ...
The subject of these images are supernatural creatures or shamans who use their hands to hold severed human heads whilst their wings transport them like birds. [2] These could be intended to represent being carried to the next world by spirits or that these figures represent the spirits themselves.
[1] [2] A palette is made of materials such as wood, paper, glass, ceramic or plastic, and can vary greatly in size and shape. [2] [3] Watercolor palettes are generally made of plastic or porcelain in a rectangular or wheel format, and have built in wells and mixing areas for colors. [4]
Some early web browsers constrained images to use a specific palette known as the web colors, leading to severe degradation in quality compared to optimized palettes. PNG images support 24-bit color, but can often be made much smaller in filesize without much visual degradation by application of color quantization, since PNG files use fewer ...
Edziza obsidian is a naturally formed volcanic glass found at the Mount Edziza volcanic complex in northwestern British Columbia, Canada. It occurs in at least four geological formations of the volcanic complex and was widely used by indigenous peoples during the pre-Columbian era .
Although seismic tomography was producing low-quality images [2] of the Earth's mantle in the 1980s, images published in a 1997 editorial article in the journal Science clearly showed a cool slab near the core-mantle boundary, [9] as did work completed in 2005 by Hutko et al., showing a seismic tomography image that may be cold, folded slab ...