Mini-Trees Suspended in Stones

By Selina Haefeli

Tiny crystal dendrites embedded inside a milky-white quartz stone give us a  cool chemistry lesson.

Moss agate is a semiprecious gemstone made of silicon dioxide usually found as fragments from weathered volcanic rocks. Moss-like crystal filaments grow in it that look like trees frozen in a snowstorm. These dendritic inclusions are made up of an element called manganese and iron oxides.

Some people use moss agate as a gemstone, believing that it has some healing properties. It’s also used for making mortars and pestles. It can be found in India, Brazil, Uruguay, central Europe and the United States.