Rhodonite

WHAT IS IT?

  • Rhodonite is a brittle manganese inosilicate (chain silicate) consisting primarily of manganese oxide (MnO, 40 - 50%) and silicon dioxide (Si02, 40 — 50%) with lesser amounts of magnesium oxide (MgO), iron oxide (FeO), and/or calcium oxide (CaO).

  • Composition: (Mn,Fe,Mg,Ca)Si03

  • Found in metamorphic rock with other manganese minerals

  • Prized for its pink to deep red color (red crystals are rare)

  • The name comes from the Greek work rhodon which means rosy

  • Often found to contain black manganese oxide veins giving it the appearance of pink with crisscrossing lines

  • Often confused with rhodochrosite (which is softer) or with thulite

  • Has a hardness of 5.5 to 6.5 (similar to feldspar), high specific gravity, and perfect cleavage

  • The official gemstone of Massachusetts

  • Some specimens tarnish black or brown when exposed to air

  • Formed in manganese rich metamorphic or hydrothermal environments

WHERE IS IT FOUND?

  • Primarily found in Australia, Brazil, Canada (mainly B.C.), England, India, Italy, Mexico, Japan, Madagascar, New Zealand, Russia

  • Some deposits are found in the states of Alaska, California, Montana, New Jersey, New Mexico, North Carolina, Rhode Island, and Washington

  • Well know localities: Broken Hill, New South Wales, Australia (deep red varieties); Mina Gerais region, Brazil; Ancash department , Dos de Mayo province, and Huallanca, Peru; Pajsbergat, Sweden; Yekaterinburg, Russia; Reppia & Civilina Mt., Italy

  • The best localities in the U.S. are: Franklin, Sussex Co., New Jersey; Betts Manganese Mine, Plainfield, Hampshire Co., Mass. ; Cumberland Hill, Providence Co., Rhode Island; Jail Hill, Haddam, Middlesex Co., ; North Carolina

  • In Washington State, collection locations include: Blewett Pass, French Creek (between Oso & Darrington off of FS Rd #2010, 48.27000 N 121.76030 W), Mt. Higgins (NW of Darrington, 48.31478 N 121.76222 W), Big Lake (SE of Mt. Vernon), Table Mountain (east of Big Lake, 48.37780 N 122.11597 W), Area east of Lake Riley (south of Oso)

WHAT IS IT USED FOR?

  • Commonly used as a gemstone for beads, cabochons, and ornamental objects

  • Was once used as a manganese ore in India

  • Well-formed transparent crystals are rare and sought after by collectors

  • The national gemstone of Russia.

  • The sarcophagus material for the graves of czars.

  • Used as a material for Easter eggs.