Haüyne  (Haüynite)
Current inventory:  0 gems
 

  
Haüyne is named after René Just Haüy (1743-1822), French pioneer in crystallography.

Discovered in 1807; IMA status: Valid (pre-IMA; Grandfathered)

Chemistry

Chemical Formula:

(Na,Ca)_4-8Al₆Si₆(O,S)₂₄(SO₄,Cl)_1-2

Sodium Calcium Aluminum Silicate Sulfur Sulfate Chloride

Molecular Weight:

1,032.43 gm

Composition:

Sodium

8.91 %

Na

12.01 %

Na₂O

Calcium

7.76 %

Ca

10.86 %

CaO

Aluminum

15.68 %

Al

29.63 %

Al₂O₃

Silicon

16.32 %

Si

34.92 %

SiO₂

Sulfur

9.32 %

S

Chlorine

1.72 %

Cl

1.72 %

Cl

-  %

Cl

-0.39 %

-O=Cl₂

Oxygen

40.29 %

O

100.00 %

96.50 %

= TOTAL OXIDE

Classification

Mineral Classification:

Silicates (Germanates)

Strunz 8th Ed. ID:

8/J.11-30

Nickel-Strunz 10th Ed. ID:

9.FB.10

9 : SILICATES (Germanates)
F : Tektosilicates without zeolitic H₂O
B : Tektosilicates with additional anions

Related to:

Sodalite Group.

Members of Group:

Sodalite Group: Haüyne, Lazurite, Nosean, Sodalite, Tsaregorodtsevite, Tugtupite, Vladimirivanovite

Varieties:

None

Synonyms:

Auina, Berzeline (of Necker), Hauynite, Marialite (of Ryllo)

Crystal Data

Crystallography:

Isometric - Hextetrahedral

Crystal Habit:

Crystals are dodecahedra or pseudo-octahedra, to 3 cm; in rounded grains.

Twinning:

On {111}, common, rarely as penetration twins; also as polysynthetic or contact twins.

Physical Properties

Cleavage:

Distinct on {110}

Fracture:

Irregular/Uneven to Conchoidal

Tenacity:

Brittle

Moh's Hardness:

5.0 - 6.0

Density:

2.40 - 2.50 (Eifel: 2.40) (g/cm³)

Luminescence:

May show reddish orange to purplish pink fluorescence under LW UV.

Radioactivity:

Not Radioactive

Optical Properties

Color:

Bright blue to greenish blue; white or shades of black, gray, brown, green, yellow, red, may be patchy; colorless or pale blue in thin section.

Transparency:

Transparent to Translucent

Luster:

Vitreous to Greasy

Refractive Index:

1.494 - 1.509 (Eifel: 1.502)  Isotropic; weakly birefringent when included

Birefringence:

0.000 (Isotropic)

Dispersion:

0.008

Pleochroism:

None

Occurances

Geological Setting:

In phonolites and related leucite- or nepheline-rich igneous rocks; less commonly in nepheline-free extrusives.

Common Associations:

Andradite, Apatite, Augite, Biotite, Leucite, Nepheline, Melilite, Phlogopite, Sanidine, Titanian.

Common Impurities:

None

Type Locality:

Lake Nemi, Alban Hills, Rome Province, Latium, Italy

Year Discovered:

1807

View mineral photos:

Haüyne Mineral Photos and Locations

More Information

Mindat.org
Webmineral.com

Haüyne, also known as Haüynite, is a member of the Sodalite Group of minerals that includes Haüyne, Lazurite, Sodalite and Tugtupite. Haüyne is also considered to be a Feldspathoid. Minerals with chemistries that are close to those of the alkalai Feldspars, but are poor in silica (SiO2) content, are called Feldspathoids. Haüyne has one of the most intense and beautiful blue colors in the gem world. It is one of the major constituents of Lapis Lazuli and accounts for the intense blue in Lapis. Faceted gems are rare and are always very small. Although Haüyne is found in several localities around the world, the Eifel region of West Germany is the only major source of gem quality material.

Distribution: In Italy, in Lazio, at many localities in the Alban Hills, as at Ariccia, Marino, Sacrofano, and Campagnaro; on Monte Somma, and near Melfi, on Monte Vulture, Campania; in the Pitigliano quarry, near Grosseto, Tuscany. From Mendig, Mayen, and elsewhere in the Eifel district, Germany. In the USA, from Winnett, Petroleum County, Montana, and in the Edwards mine, St. Lawrence County, New York. In the Niangniang Shan complex, Nanjing, Jiangsu Province, China. On the smaller island of Taiarupu, Tahiti. A few other minor localities are known.
 

  
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