Colors of Natural Stone

Rausch Granite Countertops and Monuments

As discussed previously, stone was formed from different types of natural minerals.

Granite is primarily made of Quartz, Feldspar and Potassium. It usually has a darker color and contains very little, if any, Calcite. It provides a heavy crystalline and granular appearance with mineral grains. Granite is a very hard material and easier to maintain than marble. There are different types of granite depending on the percentage mix of Quartz, Mica and Feldspar. Black granite is known as an Anorthosite. It contains very little Quartz and Feldspar and has a different composition than true granite.

Marble’s main consistency is calcium. Calcium carbonate is the natural source that bonds the stone. Certain additive minerals blended in to the calcium during formation to customize these brilliant colors. The additive minerals are also color developers present in granite and other natural stones.

Stone Color:

Mineral:

Black Biotite, Hornblende, Carbon
Brown Limonite
Gray Variety of minerals
Green Mica, Chloride, Silicate
Red Hematite
White Feldspar, Calcite, Dolomite
Yellow Limonite

Minerals have a variety of crystalline properties. A different property has a different color. For instance, Augite (listed above) has different crystalline properties. Each property has its own color. Stones brilliant colors and various crystal formations developed when different mineral properties blended together along with the integration of temperature and pressure. The veins and color grains of marble were liquid minerals that flowed through the stone wh en the Earth heated up. The intense heat softened the limestone to allow the liquids to flow through it. When the Earth cooled, the mineral flow stopped and gradually hardened to its current state.

Mineral:

Mineral Color:

Augite Brown, Green, Black, Purple
Biotite Black, Brown, Green
Calcite Pearlenscent and Pale Colors
Dolomite Colorless, Pink, Pale Brown
Feldspar Yellow, White, Pink, Green, Grey
Hematite Metallic Grey or Black
Hornblende Green, Yellow, Brown, Black
Limonite Black, Brown, or Yellow
Sulphur Pale Gold