What is the shape of the sandstone structure of the hardness of what kind of shale structure hardness
Different sandstone structure is different, such as loose sandstone, cement less loose structure, hardness is very low, such as gray sandstone, the structure is relatively hard, hardness of about 6-7. Shale is a sheet structure, plate like structure, the hardness of the composition and the degree of cementation to see the shale, shale is relatively soft, between 1-2, gray mudstone is relatively hard.
Although the granite is considered by melting forming material or magma igneous rocks, but there is a lot of evidence that some form of granite is local deformation or previous rock products, they are not through liquid or melt process and rearrange and recrystallization.The specific gravity of granite is between 2.63 and 2.75, and its compressive strength is 1050~14000 kg / cm2 (15000~20, 000 pounds / square inch). Because the intensity ratio of sandstone, granite and marble limestone, so it is difficult to mining. Due to the special conditions of granite formation and firm structure, it has the following unique properties
