Calcite is one of the most common minerals on earth.
The mineral calcite cleaves in three directions and is parallel to the rhombohedral form which means that the three angles will never be perpendicular. It only has a hardness of three so it cannot scratch glass as quartz would. When calcite is treated with dilute hcl it has a bubbling effect. It also exhibits fluorescence at times.
It’s crystal habit can be botryoidal (looks like soap bubbles), drusy, globular, rhombohedral, stalactite as a matter of fact calcite has 300 different types of crystal formations more than any other mineral! It’s most common color is clear, white, pink, yellow, orange, reds, greens but it has more colors depending on it’s included impurities.
Calcite has more uses than almost any other mineral. It can be used for construction, agriculture, pharmaceuticals, and household uses such as in paints, abrasives in cleaners not to mention those beautiful household decorations.
Tualatin Valley Gem Club 