Gold forms in close association with volcanoes or is hosted in volcanic rocks. Three environments/styles are most common: gold in greenstone belts, gold in porphyry deposits, and gold in epithermal deposits.

Intrusive rocks are formed from magma that cools and solidifies within the crust of the planet. When lava comes out of a volcano and solidifies into extrusive igneous rock, also called volcanic, the rock cools very quickly.

SOME magma forms quite deep in the lower crust, and even involves parts of the upper mantle, and those magmas sometimes contain gold (in reasonable amounts). Gold in volcanic rocks does occur, but it is not very common.

quartz rock

According to Marble.com, in 2016 there were 276 quarries producing natural stone in 34 states, and states producing the most granite were Texas, Massachusetts, Indiana, Wisconsin, and Georgia. The term “quarry” refers also to sites producing aggregate, molding sand, or other resources besides cut stone.

For instance, granite produced in China tends to have the lowest resale price due to low labor costs—just like many other products made in China. Granite from Italy and Brazil tends to be more expensive.

In some cases, schists are lumped in with slates and phyllites. This is especially true if the stone breaks into flat layers or if the mica grains are small. Some types of schist are commercially categorized as granite. This is likely if it’s leaning more toward gneiss on the metamorphic spectrum.

Hardness and Durability: Granite is extremely hard and dense. You’ll see it used in places where durability is most important, including bridges, building facades, monuments, and more. Granite is extremely heat- and scratch-resistant, since it was is formed under higher temperatures and more pressure than schist.

Schist is a medium grade metamorphic rock with medium to large, flat, sheet like grains in a preferred orientation. Granite is a very hard, granular, crystalline igneous rock which consists mainly of quartz, mica, and feldspar and is often used as building stone. These rocks are composed of many distinct minerals.

Schist Uses Presently, It is used as a decorative stone as well as for jewelry. In Australia, houses that were built using schist in the 1800s are still standing today. Mica Schist is a very interesting rock. Some uses for this rock isare decorative rock wall, pillars, paint fillers, and roofingmaterial.