Four rough stones ready to tumble! Each stone is 1-2 inches. Quartz has a Mohs hardness scale of 7.
Quartz is one of the most common minerals on earth and comes in many colors. Rose quartz emits a pink light due to miniscule amounts of titanium, manganese or iron included with the crystals.
A perfect gift for the rock hound in your life. If they don't already have a rock tumbler, you're in the right place. The Science Museum of Minnesota also sells tumbling supplies and equipment.
