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Roselite
Current inventory:  0 gems, (1 sold)
 

Roselite

  
Roselite is named in honor of Gustav Rose (1798 - 1873), professor of mineralogy at the University of Berlin, Germany.

Discovered in 1824; IMA status: Valid (pre-IMA; Grandfathered).

 

Chemistry

 

 

Chemical Formula:

Ca2(Co,Mg)(AsO4)2 • 2(H2O)

 

Hydrated Calcium Cobalt Magnesium Arsenate

Molecular Weight:

444.30 gm

Composition:

Calcium

18.04 %

Ca

25.24 %

CaO

 

Magnesium

1.37 %

Mg

2.27 %

MgO

 

Cobalt

9.95 %

Co

12.65 %

CoO

 

Arsenic

33.73 %

As

51.73 %

As2O5

 

Hydrogen

0.91 %

H

8.11 %

H2O

 

Oxygen

36.01 %

O

 

 

 

 

100.00 %

 

100.00 %

= TOTAL OXIDE

 

 

Classification

   

   

Mineral Classification:

Phosphates

Strunz 8th Ed. ID:

7/C.17-100

Nickel-Strunz 10th Ed. ID:

8.CG.10

 

8 : PHOSPHATES, ARSENATES, VANADATES
C : Phosphates without additional anions, with H
2O
G : With large and medium-sized cations, RO
4:H2O = 1:1

Related to:

Roselite Group. Roselite-Wendwilsonite Series. The monoclinc dimorph of β-Roselite. The cobalt analogue of Wendwilsonite. Isostructural with Brandtite.

Members of Group:

Roselite Group: Brandtite, Kröhnkite, Roselite, Rruffite, Wendwilsonite, Zincroselite. Closely related to the (triclinic) Fairfieldite Group.

Varieties:

None

Synonyms:

Roselith

 

 

Crystal Data

   

   

Crystallography:

Monoclinic - Prismatic

Crystal Habit:

Crystals are elongated along [100], showing {011}, {111}, {010}, {110}, to 1.3 cm; commonly in spherical aggregates and druses.

Twinning:

Very common on {100} with {100} as composition plane, contact twins and fourlings.

 

 

Physical Properties

   

 

Cleavage:

Perfect on [010]

Fracture:

Spintery

Tenacity:

Brittle

Moh's Hardness:

3.5

Density:

3.46 - 3.74 (g/cm3); density increases with Co content

Luminescence:

Not Fluorescent

Radioactivity:

Not Radioactive

Other:

Readily soluble in acids.

 

 

Optical Properties

   

   

Color:

Pale rose-pink to dark rose-pink; rose-pink in transmitted light, may be color zoned. Darker coloured crystals frequently exhibit marked color zoning due to variations in composition.

Transparency:

Transparent to Translucent

Luster:

Vitreous

Refractive Index:

1.725 - 1.735  Biaxial ( - )

Birefringence:

0.010

Dispersion:

Weak to Strong; r < v

Pleochroism:

Visible; X = pale rose-pink to dark rose-pink; Y = paler rose-pink; Z = palest rose-pink.

 

 

Occurances

   

   

Geological Setting:

A rare secondary mineral in cobalt-bearing hydrothermal mineral deposits.

Common Associations:

Talmessite (Bou Azzer, Morocco)

Common Impurities:

None

Type Locality:

Rappold Mine, Neustädtel, Schneeberg District, Erzgebirge, Saxony, Germany

Year Discovered:

1824

View mineral photos:

Roselite Mineral Photos and Locations

 

 

More Information

   

   

 

Mindat.org
Webmineral.com

 

 


Roselite is a very rare secondary mineral in cobalt-bearing hydrothermal mineral deposits. It is an extremely rare faceted gem. Gems are a beautiful pale rose-pink to dark rose-pink and always very small because crystals are small. One current source of crystals is Bou Azzer, Morocco.

Distribution: In Germany, from the Rappold and Daniel mines, Schneeberg, Saxony; at the Friedrich Christian mine, Wildschapbachtal, and the Anton mine, Heubachtal, near Schiltach, Black Forest. From Bou Azzer, Morocco. In the Talmessi mine, 35 km west of Anarak, Iran. From Huercal Overa, Almer´ia Province, and at Molvizar, Granada Province, Spain.
 

  
Roselite gems for sale:

Roselite-001

Gem:

Roselite

Stock #:

ROSE-001

Weight:

0.061 ct

Size (w x d):

2.59 x 1.33 mm

Shape:

Round

Color:

Dark Rose Red

Clarity:

SI2

Origin:

Bou Azzer, Morocco

Treatment:

None (natural)

Price:

SOLD

Pictures are of the actual gem offered for sale.
Gem images are magnified to show detail.

Roselite-001

An extemely rare gem from Bou Azzer District, Tazenakht, Ouarzazate Province, Souss-Massa-Draâ Region, Morocco. This little gem has great color!


 


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