Why Are There Color Variations In Stone?

One of the reasons many people choose natural stone for their home is that no two stones are the same. Each stone is a work of art created by Mother Nature, developed by heat, pressure and a wide range of minerals. It is this process that creates the various textures, patterns, and colors found in natural stone.


Granite is an igneous rock that solidified from molten rock. Although granite is made up mostly of quartz, feldspar, and mica but it also contains small amounts of other materials. It is these materials that give granite its color variations. A granite slab with a large amount of quartz will have a milky-white or gray tone while feldspar will give it an off-white color. If the stone contains potassium feldspar, it will have shades of salmon or pink. Biotite gives granite a dark brown or black color while muscovite adds metallic gold or yellow specks. If the granite is black or dark green, it may have amphibole while specks of violet may mean the stone has lepidolite.


Pure limestone is white or very close to white but impurities in the stone like clay, sand, iron oxide and organic remains may cause the stone to have different colors. Iron in a limestone slab may cause orange, red or brown flecks. If the slab has flecks of gray or other color, it may have shells of marine animals compressed into the stone. In fact, it is not unusual for a shell to be visible in the limestone which can make for a fun conversation piece in a countertop.


Marble is created from crystalized limestone and, if the limestone has few impurities, the slab will be a light color with very little veining. However, as marble forms other minerals penetrate the limestone, giving marble its colors and textures. Yellow or brown veining indicates that iron oxide penetrated the limestone while feldspar adds pink or red coloring. If the stone has green veining, serpentine may have penetrated the marble during formation while violet could indicate porphyry.


Quartzite is often comprised of many different materials which means it is available in a wide range of colors. Quartzite is most often white or gray and may have flakes of mica which give it a translucent look. Dumortierite can give the stone blue veining while pink or red could mean iron oxide. It is also possible to find purple, yellow or green quartzite, all created by a wide range of minerals that penetrated the stone as it formed.


Formed from clay and volcanic ash, slate is usually dark gray unless it has been infused with iron. If that occurs, the slate may have red, green, black or brown veining. Hematite may add a red or purple shade while chlorite could give the stone a greenish tint. The texture of slate can also be changed if it has mica, chlorite or quartz.

No matter which type of natural stone you are considering for your home, Marble Concepts can provide you with detailed information. Our customer service representatives can answer any question you may have and guide you through the entire process. Call us today or complete the easy form online for more information.