|Granite countertops is an intrusive rock in acidic (sio2>66%) magmatic rocks, which is the most common type of rock in this category, mostly light red, light gray, grayish white, etc. Medium coarse grain, fine grain structure, block structure. Some are also patchy structures, globular structures, and plaque-like structures. The main minerals are quartz, potassium feldspar and acid plagioclase, and the minor minerals are biotite, hornblende, and sometimes a small amount of pyroxene. There are many kinds of secondary minerals, such as magnetite, vermiculite, zircon, apatite, tourmaline, fluorite and the like. The quartz content is the most among various magmatic rocks, and its content can range from 20-50%, and a few can reach 50-60%. The content of potassium feldspar is generally more than that of plagioclase. The ratio of the content of the two is often two-thirds of the total feldspar of potassium feldspar, one third of feldspar, and more potassium feldspar in granite. It is light red and gray, gray and gray. Gray-white potassium feldspar and plagioclase are often difficult to distinguish on hand specimens. At this time, we must carefully observe the twin crystal characteristics of these two feldspars, because the plagioclase has a polycrystalline twin crystal, and when the hand specimen is rotated, there are regular bright and dark patches on the plagioclase crystal, and potassium feldspar. It is a card type twin crystal, which is expressed as two crystals with different brightness.|
Granite slabs can also be further named according to the type of dark minerals. For example, dark minerals are mainly biotite, which can be called biotite granite, which is a common type of granite. For example, the biotite and muscovite are nearly equal in content and can be called two mica granite. If the dark mineral is mainly amphibole, it is called hornblende granite. If the dark mineral is mainly pyroxene, it is called hui. Stone granite, which contains almost no dark minerals, can be called white granite .