Metamorphic rock

Metamorphic rock is the natural metamorphism of one kind of stone into another under the combination of high temperature, high pressure and minerals.A qualitative change may be recrystallization, a change in texture or a change in color.

1,Marble: it is recrystallized limestone, limestone at high temperature and high pressure become soft, and in the mineral content changes when the formation of recrystallized marble.The main composition is calcium and dolomite, a variety of colors, usually with a distinct pattern, many mineral particles.Mohs are between 2.5 and 5.

Marble is divided into three categories:

Dolomite: Magnesite (calcium and magnesium carbonate) content of more than 40%

Magnesium olivine: Magnesite (calcium and magnesium carbonate) content between 5% and 40%.

Calcite: Magnesite (calcium and magnesium carbonate) content less than 5%

2. Slate: Metamorphic rock formed from claystone, sedimentary shale (and sometimes quartz), with fine, thin, brittle mineral grains, usually black, gray, or green.

3.Serpentine: Named for its snakeskin pattern, the most common colors are green and brown.Mohs hardness ranges from 2.5 to 4.Contains large amounts of magnesium, originating from igneous rock.The effect of recrystallization and diamond polishing is sometimes poor.