Trolleite (inslusion in Quartz)
Current inventory:  1 gem
 

  
Trolleite is named after Hans Gabriel Trolle-Wachmeister (1782-1871), Swedish chemist.

Discovered in 1868;   IMA status:  Valid (pre-IMA; Grandfathered)

Chemistry

Chemical Formula:

Al₄(PO₄)₃(OH)₃

Aluminum Phosphate Hydroxide

Molecular Weight:

443.86 gm

Composition:

Alumium

24.32 %

Al

45.94 %

Al₂O₃

Phosphorus

20.93 %

P

47.97 %

P₂O₅

Hydrogen

0.68 %

H

6.09 %

H₂O

Oxygen

54.07 %

O

100.00 %

100.00 %

= TOTAL OXIDE

Classification

Mineral Classification:

Phosphates

Strunz 8th Ed. ID:

7/B.08-10

Nickel-Strunz 10th Ed. ID:

8.BB.45

8 : PHOSPHATES, ARSENATES, VANADATES
B : Phosphates, etc., with additional anions, without H₂O
B : With only medium-sized cations, (OH, etc.):RO₄ about 1:1

Related to:

n/a

Varieties:

None

Synonyms:

None

Crystal Data

Crystallography:

Monoclinic - Prismatic

Crystal Habit:

Lamellar, massive, to 3 cm

Twinning:

None

Physical Properties

Cleavage:

Poor/Indistinct in two directions

Fracture:

Irregular/Uneven, Sub-Conchoidal

Tenacity:

Brittle

Moh's Hardness:

8.5

Density:

3.08 (g/cm³)

Luminescence:

Not fluorescent

Radioactivity:

Not Radioactive

Optical Properties

Color:

Light or pale Green, Colorless, Bluish Green, bright Blue (dark Blue when included). May be very blue because of mixtures with Scorzalite.

Transparency:

Transparent to Translucent

Luster:

Vitreous

Refractive Index:

1.619 - 1.643  Biaxial ( - ) 

Birefringence:

0.024

Dispersion:

Weak to Strong; r > v or v < r

Pleochroism:

None

Occurances

Geological Setting:

In amphibolite-grade metamorphic rocks. Peraluminous high pressure rocks.

Common Associations:

Berlinite, Attakolite, Augelite, Lazulite (Västanå mine, Sweden); Scorzalite, Augelite, Viséite (Champion mine, California, USA); Montebrasite, Scorzalite, Bertossaite, Brazilianite, Apatite, Gatumbaite, Samuelsonite, Wyllieite (Buranga pegmatite, Rwanda).

Common Impurities:

None (Scorzalite-Lazulite may be admixed)

Type Locality:

Västanå Iron Mine (Westanå Mine), Näsum, Bromölla, Skåne, Sweden

Year Discovered:

1868

View mineral photos:

Trolleite Mineral Photos and Locations

More Information

Mindat.org
Webmineral.com

Trolleite is a rare phosphate mineral that is unusually hard at about 8.5 on the Mohs scale. It was originally named by Blomstrand in 1869 for Hans Gabriel Trolle-Wachmeister (1782-1871), a Swedish chemist. It was discovered at a small iron ore deposit at Västanå Iron Mine (Westanå Mine), Skåne, Sweden. Trolleite is often associated with other phosphate minerals such as Augelite, Lazulite, Montebrasite and Scorzalite. Trolleite is found in colors of light to pale green, colorless, bluish green, bright blue (dark blue when included) and may be very blue because of mixtures with Lazulite or Scorzalite.

A recent find of Quartz containing heavy inclusions of Trolleite and Lazulite was presented for the first time at the 2011 Tucson Gem Show. This new material is from Minas Gerais, Brazil and was submitted to the Mineralogical Museum of the University of Rome as well as the Italian National Research Counsil's Institute of Environmental Geology in Rome for standard gemological testing techniques as well as testing by a Camaca SX-50 electron microprobe. This testing identified the blue inclusions in Quartz as Trolleite and Lazulite. This new material from Brazil is translucent to opaque with fairly even light to medium blue color.

Distribution: At the Type Locality in Sweden, from the Västanå mine, near Näsum, Skäne; also at Hälsjöberg, Värmland; from Hökensås, Västergötland. A recent find from Minas Gerais, Brazil. In the Buranga pegmatite, Rwanda. On Mt. Perry, 75 km southwest of Bundaberg, Queensland, Australia. In the USA, at the Kyanite Corporation mine on Willis Mountain, Buckingham County, Virginia; four km west of Glendevey, Larimer County, Colorado; in the Champion mine, White Mountains, Mono County, California.
 

  
Trolleite gems for sale: