This section entry will introduce three major types of stones and give their advantages and disadvantages.
Introduction to Granite
Granite is a light-colored igneous rock with grains so large they can be seen by the naked eye. Granite is primarily made of quartz and feldspar with minor amounts of amphiboles, mica, and other minerals. The slow crystallization of magma below Earth's surface forms granite. This mineral composition generally gives granite a red, pink, gray, or white composition with dark mineral grains visible throughout the rock. Granite is the best-known igneous rock. Many people know about granite because it makes many objects that people encounter and use in daily life. These comprise counter tops, floor tiles, paving stones, stair treads, curbs and curbing, building veneers, and cemetery monuments.
Marble is a metamorphic rock that is created when limestone is subjected to the heat and pressure of metamorphism. It is mainly made of the mineral calcite and generally contains other minerals, such as clay minerals, micas, quartz, pyrite and graphite. Under metamorphism, the calcite in limestone recrystallizes to form a rock that is a mass of interlocking calcite crystals. A linked rock, called dolomitic marble, is produced when dolostone is subjected to heat and pressure.
Most marble forms at convergent plate limitations where large areas of the Earth's crust are bare to regional metamorphism. Some marble also forms by contact metamorphism when a hot magma body heats nearby limestone or dolostone.
Quartzite is a nonfoliated metamorphic rock made almost entirely of quartz. It forms when a quartz-rich sandstone is changed by the heat, pressure, or chemical activity of metamorphism. These occurrences recrystallize the sand and the silica cement that bind them together. The result is a network of interlocking quartz grains that are incredibly strong. The stone is so hard that it breaks through the quartz grains rather than breaking along the boundaries between them. This is a feature that separates true quartzite from sandstone. Pure quartzite is usually white or grey, through quartzite often comes in various shades of pink and red, due to varying amounts of iron oxide. Other colors such as yellow, green, blue and orange are due to other mineral impurities.