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| Witherite
is named after Dr. William Withering (1741-1799),
English physician and mineralogist, who first noted
the material.
| Discovered
in 1790;
IMA
status:
Valid (pre-IMA; Grandfathered) |
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Chemistry
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Chemical
Formula: |
Ba(CO3)
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Barium Carbonate
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Molecular
Weight: |
197.34 gm
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Composition: |
Barium |
69.59 % |
Ba |
77.70 % |
BaO |
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Carbon |
6.09 % |
C |
22.30 % |
CO2 |
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Oxygen |
24.32 % |
O |
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100.00 % |
|
100.00 % |
= TOTAL OXIDE |
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Classification
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Mineral
Classification: |
Carbonates
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Strunz 8th
Ed. ID:
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5/B.04-30
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Nickel-Strunz 10th
Ed. ID:
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5.AB.15
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5 : CARBONATES (NITRATES)
A : Carbonates without additional anions, without H2O
B : Alkali-earth (and other M2+) carbonates
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Related
to: |
Aragonite
Group. Strontianite
- Witherite Series.
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Members
of Group: |
Aragonite
Group: Aragonite, Cerussite, Strontianite, Witherite
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Varieties: |
None
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Synonyms: |
Aerated Barytes,
Barolite, Barolite (of Kirwan), Sulphato-Carbonate of Baryta,
Viterite
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Crystal
Data
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Crystallography:
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Orthorhombic - Dipyramidal
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Crystal
Habit:
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Pseudohexagonal
dipyramidal due to repeated twinning, short prismatic
to elongated along [001], {010}, {021}, {012}, other
faces commonly rough and horizontally striated, to 12
cm. May be botryoidal to spherical, columnar fibrous,
granular, massive.
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Twinning:
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On {110},
universal
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Physical
Properties
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Cleavage: |
Distinct
on {010}, poor on {110} and {012}
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Fracture: |
Sub-Conchoidal
to Irregular/Uneven
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Tenacity:
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Brittle
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Moh's
Hardness: |
3.0
- 3.5
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Density:
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4.22
- 4.31 (g/cm3)
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Luminescence:
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Bluish
white under SW UV with phosphorescence (green and
yellow in material from England); bluish white
under LW UV with phosphorescence (yellowish in material from England); Fluoresces in X-rays
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Radioactivity:
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Not
Radioactive
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Health
Warning: |
CAUTION:
Barium Carbonate is toxic if ingested. Handling of Witherite is not a
major cause of concern as long as you avoid breathing in dust and wash your hands after handling.
|
Other: |
Effervesces in dilute HCl solutions;
soluble in dilute HCl
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Optical
Properties
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Color: |
Colorless,
white, pale gray, may be tinted pale yellow, pale brown,
or pale green; colorless in transmitted light |
Transparency: |
Transparent to Translucent
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Luster: |
Vitreous;
resinous on fractures |
Refractive
Index: |
1.529 - 1.677 Biaxial
( - ) |
Birefringence: |
0.1480
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Dispersion: |
Very weak;
r > v
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Pleochroism: |
None
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Occurances
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Geological
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. |
Common
Associations: |
Barite,
Calcite, Fluorite, Galena |
Common
Impurities: |
Ca,
Sr |
Type
Locality: |
Brownley Hill Mine (Bloomsberry Horse Level), Nenthead,
Alston Moor District, North Pennines, North and Western Region (Cumberland),
Cumbria, England, UK |
Year
Discovered: |
1790
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View
mineral photos: |
Witherite
Mineral Photos and Locations |
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More
Information
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|
Mindat.org
Webmineral.com
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Witherite
is a rare member of the Aragonite group of minerals
that also includes Aragonite and
Cerussite.
Witherite
is very rarely faceted because it is soft, fragile and
difficult to polish. It is an interesting mineral in that its crystals
always form twins.
All members of the Aragonite group can form twins, but
Witherite is one member that always forms twins!
Witherite gems typically have a pearly luster or internal
"sleepiness" similar to Prehnite.
Witherite fluoresces a beautiful bluish white
under both short wave and long wave UV light with phosphorescence.
Notable occurances of Witherite are Cave-in-Rock, Hardin
County,
Illinois, USA; Alston Moor, Cumberland and Durham, England;
Thunder Bay area, Ontario, Canada.
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Witherite
gems for sale:
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Gem:
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Witherite |
Stock
#:
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WITHER-001 |
Weight:
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3.4035
ct |
Size: |
9.06
x 9.02 x 5.84 mm |
Shape: |
Custom
Trillion |
Color: |
Very
Pale Yellowish White |
Clarity: |
Eye
Clean - VSI (sleepy) |
Origin: |
Cave-in-Rock,
Illinois, USA |
Treatment: |
None
(natural) |
Price: |
$680.00
[
Make an offer ] |
Pictures
are of the actual gem offered for
sale. Gem images are magnified to
show detail. |
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|
An
extremely rare gem with a very nice
glow of very pale yellowish white color
with a sleepy appearance similar to
the effect visible in Prehnite
gems. This beautiful gem is from
a classic US location; Cave-in-Rock,
Hardin County, Illinois. A location
also known for its beautiful Flourite
specimens. This beautiful gem was precision faceted
in the US.
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