Rock & Gem Kids: Manganoan Calcite

By Jim Brace-Thompson

Calcite comes in a remarkable variety of shapes and colors. One beautiful variety that is highly sought by collectors is manganoan calcite. Also called manganocalcite, pink mangano calcite, or pink magnesium calcite, it has the chemical formula of (Ca,MN)CO3. What makes manganoan calcite so beautiful is its delicate pink hue and gemmy translucence. The lovely pink hue is thanks to manganese.

When pure, calcite is colorless or white. The more manganese included within the calcite, the redder the color, all the way up to “rose colored”. If the proportion of manganese versus calcium exceeds 50 percent, the color intensifies to red. This deeper red variety is called rhodochrosite. In other words, there is a continuum that goes from calcite (CaCo3) to rhodochrosite (MnCO3), and manganoan calcite falls approximately midway within this continuum.

More Maganese Means More Red Coloring

Not only is this variety of calcite beautiful on its own under visible light, when placed under ultraviolet (UV) light, it glows a spectacular orange color and is often phosphorescent, meaning that it glows momentarily even after a UV light is switched off. In Medieval times, physicians believed this mineral could relieve ailments of the blood, perhaps because of its pink-to-red color. Today’s metaphysical practitioners refer to this mineral as a “calming stone” to fill one’s heart with both universal and self-love, thus relieving anxiety, stress, and fear.

The manganoan variety of calcite was first reported from the Banska Stiavnica Mining District of Slovakia, home to my own son-in-law. But it has also been found in many other countries in Europe and around the world. For instance, the specimen shown here is from Peru. It has also found in such diverse areas as China, Russia, Argentina, Mexico, Australia, Canada, Japan, Turkey, South Africa, the United States, and many other countries. Wherever found, manganoan calcite is valued for its lovely pink beauty.