Granite is made up of about 35% quartz, 45% feldspar, mica, potassium and very little calcite, if any. The ratio of these materials can vary, resulting in different types of granite. Typically, it is a darker hue but can come in a wide variety of colors. Granite is one of the hardest materials on earth. It is a highly durable material and is resistant to heat, cooking acids (lemon juice, vinegar, etc.) and scratches. You will only dull your knives if you use granite as your cutting board. It is highly sanitary, resisting bacteria like salmonella and other typical household germs.