Click on a letter above to view the list of gems.    

  

 


Amblygonite
Current inventory:  1 gem
 

Amblygonite

  
The name Amblygonite is from the Greek words ambly for blunt and goni for angle,
referring to the fact that its cleavage angle slightly differs from 90, distinguishing it from scapolite for which it was originally mistaken.

Discovered in 1818;   IMA status: Valid (pre-IMA; Grandfathered)

 

Chemistry

 

 

Chemical Formula:

LiAl(PO4)(F,OH)

 

Lithium Aluminum Phosphate Fluoride Hydroxide

Molecular Weight:

151.41 gm

Composition:

Sodium

3.80 %

Na

5.12 %

Na2O

 

Lithium

3.44 %

Li

7.40 %

Li2O

 

Aluminum

17.82 %

Al

33.67 %

Al2O3

 

Phosphorus

20.46 %

P

46.88 %

P2O5

 

Hydrogen

0.17 %

H

1.49 %

H2O

 

Oxygen

44.91 %

O

 

 

 

Fluorine

9.41 %

F

9.41 %

F

 

 

  %

F

3.96 %

O=F2

 

 

100.00 %

 

100.00 %

= TOTAL OXIDE

 

 

Classification

   

   

Mineral Classification:

Phosphates

Strunz 8th Ed. ID:

7/B.02-30

Nickel-Strunz 10th Ed. ID:

8.BB.05

 

8 : PHOSPHATES, ARSENATES, VANADATES
B : Phosphates, etc., with additional anions, without H
2O
B : With only medium-sized cations, (OH, etc.):RO
4 about 1:1

Related to:

Amblygonite Group. Griphite-Tavorite Series.

Members of Group:

Amblygonite Group: Amblygonite, Montebrasite, Natramblygonite, Natromontebrasite, Tavorite

Varieties:

Hebronite

Synonyms:

None

 

 

Crystal Data

   

   

Crystallography:

Triclinic - Pinacoidal

Crystal Habit:

Crude crystals, typically equant with complex form development, to 1.5 m; massive.

Twinning:

On several laws, with microscopic polysynthetic twinning common.

 

 

Physical Properties

   

 

Cleavage:

[100] Perfect, [110] Good, [011] Distinct

Fracture:

Irregular/Uneven, Sub-Conchoidal

Tenacity:

Brittle

Moh's Hardness:

5.5 - 6.0

Density:

3.04- 3.11 (g/cm3)

Luminescence:

None

Radioactivity:

Not Radioactive

 

 

Optical Properties

   

   

Color:

Milk-white, yellowish, beige, salmon-pink, greenish, bluish, grey

Transparency:

Transparent, Translucent

Luster:

Vitreous to Greasy, Pearly on good cleavages

Refractive Index:

1.578 - 1.613  Biaxial ( - )

Birefringence:

0.020 - 0.030

Dispersion:

r > v

Pleochroism:

None

 

 

Occurances

   

   

Geological Setting:

An uncommon accessory mineral in zoned granite pegmatites; in high-temperature tin veins and greisens.

Common Associations:

Lacroixite, Apatite, Lithiophilite, Spodumene, Lepidolite, Petalite, Pollucite, Tourmaline (pegmatites); Cassiterite, Topaz, Mica (greisens).

Common Impurities:

None

Type Locality:

Chursdorf, Penig, Chemnitz, Saxony, Germany

Year Discovered:

1818

View mineral photos:

Amblygonite Mineral Photos and Locations

 

 

More Information

   

   

 

Mindat.org
Webmineral.com

 

 


Amblygonite is a beautiful gem usually pale straw yellow. Darker, more saturated "lemon" yellow gems are rarer and more highly prized. An extremely rare lilic colored Amblygonite comes from Karibib, Namibia. Amblygonite is very closely related to Montebrasite and varies only by optiacal property. Amblygonite is optically (-) and Montebrasite is optically (+). It may be that if many Amblygonite gems where retested, they may actually be Montebrasites. In general, it is thought that most yellow gems on the market are Amblygonite, and most colorless gems are Montebrasite, but this does not always hold true.

The few localities for analyzed material include: from Chursdorf and Arnsdorf, near Penig, Saxony, Germany. On Ut Island, near Stockholm, Sweden. In the USA, at Hebron, Oxford County, Maine; large crystals in San Domingo Wash, northeast of Wickenburg, Maricopa County, Arizona. From the Tanco pegmatite, Bernic Lake, Manitoba, Canada. At Coolgardie, Western Australia. From near Karibib, Namibia. In the Muine pegmatite, Alto Ligonha district, Mozambique.
 

  
Amblygonite gems for sale:

Amblygonite-001

Gem:

Amblygonite

Stock #:

AMBLY-001

Weight:

1.2230 ct

Size:

7.39 x 5.93 x 3.67 mm

Shape:

Trillion

Color:

Mint Green

Clarity:

MI2

Origin:

Mina Morro Redondo, Coronel Murta, Minas Gerais, Brazil

Treatment:

None

Price:

SOLD (but we have others)

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

Amblygonite-001

This mint green Amblygonite is a rare color for the type. It is a bright and beautiful gem with a checker board table.


Amblygonite-002

Gem:

Amblygonite

Stock #:

AMBLY-002

Weight:

11.6285 ct

Size:

16.43 x 16.70 x 8.04 mm

Shape:

Trillion

Color:

Yellow

Clarity:

VS2

Origin:

Brazil

Treatment:

None

Price:

$520.00    [ Make an offer ]

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

Amblygonite-002

This one is very large and very clean for Amblygonite. It is almost eye clean with a very few inclusions that are barely visible.

 


I love Sarah