Obsidian white dating leinart dating

(Silicon dioxide also known as silica from latin silex meaning flint stone) in water.Chemically, Obsidian closely resembles granite and rhyolite but the processes which lead to the formation of Obsidian are different to those which shape granite.Like all glass and some other types of naturally occurring rocks Obsidian breaks with a characteristic "conchoidal" fracture.Also like other glass, Obsidian is metastable at the earth's surface which means that over time the glass becomes fine-grained mineral crystals.The technique measures the microscopic amount of water absorbed into freshly broken surfaces.The longer the artifact's surface has been exposed, the thicker the hydration band will be.Although excellent quality obsidian specimens can sometimes be produced by surface lava flows, the best quality of Obsidian forms around volcanic vents just below the ground.As the lava squeezes in between rocks it forms layers of Obsidian that are relatively clear of impurities.

obsidian white dating-80obsidian white dating-89obsidian white dating-79obsidian white dating-9

The 1967 field season was led by Roderick Sprague, while Ph. Through the study of Granite Point’s archaeological collection, this archaeologically important site has the potential to further its contributions to understandings of prehistoric life in the Lower Snake River Region.Obsidian is found in a number of US states, the biggest deposits being within the calderas of Newberry Volcano and Medicine Lake Volcano in the Cascade Range of western North America.The ancient volcanic hills called Glass Buttes in Oregano hold a large variety of gem-quality obsidian, including: mahogany, red, flame, midnight lace, jet black, pumpkin, brown, rainbow, gold sheen, silver sheen, green, lizard skin, snowflake etc, so if you ever thought that Obsidian is just boring black glass, the trip to those parts might be an eye-opener.The process can be sped up in the presence of water.This also means that Obsidian is only found in relatively modern areas, and in none older than the Cretaceous age (from 135 million to 63 million years ago).

Leave a Reply