Explosion Blue is a quartzite from India. It is a metamorphic rock that is formed when sandstone is subjected to extreme heat and pressure caused by tectonic plate compression under the earth's crust. Quartzite has the look and feel of marble but is actually harder than granite. When properly sealed, quartzite offers an easily cleaned and highly sanitary and bacteria free surface. It is ideal for interior use including kitchen and bathroom counter tops, tub decks, fireplace surrounds, bar tops and more.