Mineral Information and Data:

BaCO3 [CNMNC approved formula]

Named for W. Withering, English physician.

IMA status : Valid species (Pre-IMA 1790) Grandfathered
(8th edition) :  
  (14) Anhydrous Carbonates
  (14.01) with Simple Formula A+ CO3
  (14.01.03) Aragonite Group (Orthorhombic: Pmcn)
(10th edition) :
  (05) Carbonates and Nitrates
  (05.A) Carbonates without additional anions, without H2O
  (05.AB) Alkali-earth (and other M2+) carbonates
Crystal system: Orthorhombic System
Point group (H-M): mmm (or 2/m 2/m 2/m) — dipyramidal
Unit cell: a = 5.314 Å, b = 8.904 Å, c = 6.430 Å
Crystal Habit: Crystals pseudohexagonal dipyramids formed by twinning, or tabular or short prismatic, with convex base, massive
Twinning: Universal on {110}, repeated resulting in pseudohexagonal dipyramids
Color: Colorless, white, gray, may have pale yellow, greenish or brown tint
Diaphaneity: Transparent, Translucent
Luster: Vitreous, Resinous
Hardness (Mohs): 3 to 3.5
Measured Density: 4.29 g/cm3
Cleavage: 2; {010} distinct, {110} imperfect
Fracture: Uneven
Streak: White
Polymorphism and Series: Forms a series with strontianite.
Geologic Setting: Usually in minor amounts in low-temperature hydrothermal veins, typically an alteration product of barite; may be of anoxic sedimentary origin, barium supplied by volcanic hot-spring activity; uncommon in coal measures.
Mineral Association: Barite, fluorite, calcite, galena
Ore deposits: A minor production source of barium.
Synonyms/varieties: Aerated barytes, Barolite, Sulphato-Carbonate of Baryta, Viterite
Luminescent Properties: Fluorescent and phosphorescent under UV, X-rays, and electron beams.
Other Properties: Gemstone Extremely Rare.


Origin: Minerva #1 mine, Hardin Co., Illinois, USA
Sample size: 5 x 5 x 4 cm
Photo: Tom Loomis


Witherite with small crystals of alstonite
Origin: Bethel Level, Minerva #1 Mine, Cave-in-Rock District,
Hardin County, Illinois, U.S.A.
mined circa 1950s-1960s
Sample size: 4 x 4 x 3 cm
Photo: Rob Lavinsky


Witherite (with twinning) under SW-UV light
Origin: Rosiclaire, Illinois, U.S.A.
Photo and Owner: Axel Emmermann


Origin: Pigeon Roost Mine, Pike County, Arkansas, U.S.A.
Sample size: 5 x 3.5 x 3 cm
Photo: Rob Lavinsky