What is the volcanic glass?

volcanic glass is what is naturally formed when high viscosity molten lava cools. Glass is formed because this lava contains less water and more crystalline material. Its chemical composition is similar to the composition of granite, which consists of alkaline feldspar and quartz. Materials in magma, water content and cooling speed contribute to a number of natural glasses.

Magma can crystallize when cooling. The higher the viscosity of the lava, the more likely it is to turn into glass. Igneous rock is also made from lava cooling and often contains crystal particles. Most of the Earth's crust consists of igneous rock material. While the obsidian can be created with different crystals, it has a high content of silica. This glass is usually black, but the presence of hematite can also create brown, green and red shades. Mount Hellka in Iceland is one of the volcanoes known for the production of Obsidian. Although it is a glass, it is also considered a natural gem. Has a low content of the NAEmičitý and creates when he does not cook lava very quickly. This glassy rock is commonly black with thin brown sections. Magnetite granules can also be found in Tachylyte. This type of volcanic glass can be found in the Hawaiian Islands and on the inner Hebrides of Scotland.

Pele's tears are small pieces of lava that have cooled quickly. These pieces become tears and black. Glass was often found in Hawaii and was named for the Hawaiian goddess volcano. Apache tears are another type of black volcanic glass. These pieces of obsidian in the shape of a tears can be translucent when they are held to light and sometimes include shades of brown or red.

Pumicite is a volcanic ash and is very abrasive. It contains very small volcanic glass particles. Ashes can be used for polishing and grinding. The pearlite is a volcanic rock that can be used as an insulator when building a building. This can also be found in watering soils,where it is used to improve drainage and aeration.

spontaneous changes, devitrification, occur in volcanic glass to become a stone. These changes often begin in areas where larger crystals or cracks are present in the glass. Over time, the glass becomes crystals of feldspar, tridymity and quartz. This process occurs for a long time - up to millions of years - but most of the volcanic glass found is less than 65 million years.