Blödite (Bloedite)
Current inventory:  0 gems
 

  
Blödite is named to honor German chemist Carl August Blöde (1773–1820).

Discovered in 1821;   IMA status: Valid (pre-IMA; Grandfathered)

Chemistry

Chemical Formula:

Na₂Mg(SO₄)₂ • 4H₂O

Hydrated Sodium Magnesium Sulfate

Molecular Weight:

334.47 gm

Composition:

Sodium

13.75 %

Na

18.53 %

Na₂O

Magnesium

7.27 %

Mg

12.05 %

MgO

Hydrogen

2.41 %

H

21.54 %

H₂O

Sulfur

19.17 %

S

47.87 %

SO₃

Oxygen

57.40 %

O

100.00 %

100.00 %

= TOTAL OXIDE

Classification

Mineral Classification:

Sulfates

Strunz 8th Ed. ID:

6/C.18-10

Nickel-Strunz 10th Ed. ID:

7.CC.50

7 : SULFATES (selenates, tellurates, chromates, molybdates, wolframates)
C : Sulfates (selenates, etc.) without additional anions, with H₂O
C : With medium-sized and large cations

Related to:

Blödite Group. Blödite - Konyaite Series.

Members of Group:

Blödite Group: Blödite, Nickelblödite, Leonite, Mereiterite, Changoite

Varieties:

Natronkalisimonyit

Synonyms:

Astrachanite, Astrakanite, Astrakhanite

Crystal Data

Crystallography:

Monoclinic - Prismatic

Crystal Habit:

Crystals equant to prismatic [001], with complex development, as with prominent {110}, {210}, {011}, {001}, {111}, {211}, and many others, to 10 cm; granular to compact massive.

Twinning:

None

Physical Properties

Cleavage:

None observed

Fracture:

Conchoidal

Tenacity:

Brittle

Moh's Hardness:

2.5 - 3.0

Density:

2.218 - 2.240 (g/cm³)

Luminescence:

None

Radioactivity:

Not Radioactive

Readily soluble in cold water.

Optical Properties

Color:

Colorless, may be dark Gray, Bluish Green, or Reddish from inclusions; Colorless in transmitted light

Transparency:

Transparent to Translucent

Luster:

Vitreous

Refractive Index:

1.483 - 1.487  Biaxial ( - )

Birefringence:

0.0040

Dispersion:

Relatively Strong

Pleochroism:

None

Occurances

Geological Setting:

In lacustrine salt deposits and salt efflorescences; probably a product of metamorphism of marine salt deposits; in nitrate deposits; may be a volcanic sublimate.

Common Associations:

Carnallite, Halite, Kainite, Polyhalite (marine salt deposits); Halite, Mirabilite, Thénardite (lacustrine salt deposits)

Common Impurities:

None

Type Locality:

Ischler Salzberg, Perneck, Bad Ischl, Upper Austria, Austria

Year Discovered:

1821

View mineral photos:

Blödite Mineral Photos and Locations

More Information

Mindat.org
Webmineral.com

Blödite, also spelled Bloedite, is a very rare sulfate mineral that is extremely rare as a faceted gem. A faceted Blödite gem would be an odity for collectors. Blödite forms in marine and non-marine (lacustrine) evaporite deposits.

Blödite also forms as an efflorescence on cave and mine walls. An efflorescent mineral is one that forms as a precipitate from minerals in the air. Blödite crystals are very rare. Blödite crystals and gems should be stored in a sealed container to prevent them from drying out and crumbling. Possibly the only locality for gem quality crystals is Soda Lake, Carrizo Plain, San Luis Obispo County, California, USA.

Blödite is found in a limited number of localities worldwide. The few notable localities are Willi Agatz Mine, Dresden, Saxony, Germany; Astrakhan', Astrakhan' Oblast', Volga Region, Russia; and Soda Lake, Carrizo Plain, San Luis Obispo County, California, USA.
 

  
Blödite gems for sale:

We have not photographed our Blödite gems yet. Please check back soon.