Rhodochrosite (whose name means rose-colored) is a very attractive mineral  of a ore of manganese with an absolutely one-of-a-kind, beautiful color and amazing patterns  that makes it a very popular mineral.  This material was mined in Argentina

Rhodochrosite is a manganese carbonate mineral with chemical composition MnCO₃. In its (rare) pure form, it is typically a rose-red color, but impure specimens can be shades of pink to pale brown. It streaks white, and its Mohs hardness varies between 3.5 and 4. Its specific gravity is between 3.5 and 3.7. It crystallizes in the trigonal system, and cleaves with rhombohedral carbonate cleavage in three directions. Crystal twinning often is present. It is transparent to translucent with refractive indices of nω=1.814 to 1.816,nε=1.596 to 1.598. It is often confused with the manganese silicate, rhodonite, but is distinctly softer.