Kornerupine
Current inventory: 0 gems
 

  
Kornerupine was named in 1884 by Danish mineralogist Johannes Theodor Lorenzen (1855-1884) in honor of Danish geologist Andreas Nikolaus Kornerup (1857-1883).

Discovered in 1884; IMA status: Valid (pre-IMA; Grandfathered)

Chemistry

Chemical Formula:

(Mg,Fe²⁺)₄Al₆(Si,Al,B)₅O₂₁(OH)

Magnesium Iron Aluminum Boro-silicate Hydroxide

Molecular Weight:

734.04 gm

Composition:

Sodium

0.03 %

Na

0.04 %

Na₂O

Lithium

0.04 %

Li

0.08 %

Li₂O

Calcium

0.05 %

Ca

0.08 %

Ca₂O

Magnesium

11.52 %

Mg

19.11 %

MgO

Titanium

0.07 %

Ti

0.11 %

TiO₂

Aluminum

24.48 %

Al

46.26 %

Al₂O₃

Iron

1.22 %

Fe

1.57 %

FeO

Silicon

14.04 %

Si

30.04 %

SiO₂

Boron

0.46 %

B

1.47 %

B₂O₃

Hydrogen

0.14 %

H

1.21 %

H₂O

Oxygen

47.93 %

O

Fluorine

0.03 %

F

0.03 %

F

—

 —  %

F

-O=F₂

100.00 %

99.98 %

= TOTAL OXIDE

Classification

Mineral Classification:

Silicates (Germanates)

Strunz 8th Ed. ID:

8/B.31-10

Nickel-Strunz 10th Ed. ID:

9.BJ.50

9 : SILICATES (Germanates)
B : Sorosilicates
J : Sorosilicates with Si₃O₁₀, Si₄O₁₁, etc. anions; cations in octahedral [6] and greater coordination

Related to:

Kornerupine-Prismatine Series.

Varieties:

None

Synonyms:

Kornerupite

Crystal Data

Crystallography:

Orthorhombic - Dipyramidal

Crystal Habit:

Crystals prismatic, to over 20 cm, rarely terminated; also as radiating aggregates and distinctly fibrous forms.

Twinning:

None

Physical Properties

Cleavage:

Distinct on [110]

Fracture:

Irregular/uneven, conchoidal

Tenacity:

Brittle

Moh's Hardness:

6.0 - 7.0

Density:

3.28 - 3.35 (g/cm³)

Luminescence:

None

Radioactivity:

Not Radioactive

Optical Properties

Color:

Colorless, white, bluish green, green, dark green, greenish yellow, yellowish brown, black

Transparency:

Transparent to translucent and opaque

Luster:

Vitreous

Refractive Index:

1.660 - 1.684  Biaxial ( - ); may be pseudouniaxial ( - )

Birefringence:

0.013 - 0.014

Dispersion:

r > v or r < v;  0.018

Pleochroism:

Distinct; X = colorless to green; Y = colorless, pale brownish yellow, pale yellowish green; Z = pale brownish green, green, light amber

Occurances

Geological Setting:

In boron-rich volcanic and sedimentary rocks subjected to amphibolite to granulite facies metamorphism; in metamorphosed anorthosite complexes.

Common Associations:

Sapphirine, Cordierite, Spinel, Corundum, Tourmaline, Grandidierite, Dumortierite, Kyanite, Sillimanite, Andalusite, Biotite, Phlogopite, Magnetite, Ilmenite, Hematite, Rutile

Common Impurities:

Ti ,Mn, Ca, Li, Na, F

Type Locality:

Fiskenaes old harbour, Fiskenaes (Fiskenaesset; Qeqertarsuatsiaat), Nuuk (Godthåb), Kitaa (West Greenland) Province, Greenland

Year Discovered:

1884

View mineral photos:

Kornerupine Mineral Photos and Locations

More Information

Mindat.org
Webmineral.com

Kornerupine is a rare gemstone that is available in shades of green, bluish green, yellowish green and yellowish brown. The most desirable gems are the emerald green gems from Sri Lanka and Tanzania that are colored green by the presence of vanadium. Beautiful bluish green Kornerupine gems come from Madagascar and cats eye cabochons are available from Sri Lanka. Star Kornerupine has been found in Mogok, Myanmar (Burma) but is very rare. Kornerupine was originally found in Greenland as non-gemmy, radiating crystals but later found there as dark green gemmy crystals.

Kornerupine was named in 1884 by Danish mineralogist Johannes Theodor Lorenzen (1855-1884) in honor of Danish geologist, Andreas Nikolaus Kornerup (1857-1883). Kornerup died at age 26 from a lung disease he contracted while on an expedition in Greenland. Although Kornerup died at such a young age, he managed to establish himself as a well respected geologist in Greenland research. Coincidentally, Johannes Lorenzen also died at a young age, 29, while on an expedition in Greenland in 1884.

Current sources of gem quality crystals are Ivohibe District, Horombe Region, Fianarantsoa Province, Madagascar; Mogok Township, Pyin-Oo-Lwin District, Mandalay Division, Burma (Myanmar); Matara District, Southern Province, Sri Lanka; Lelatema Mts, Simanjiro District, Manyara Region, Tanzania.

Kornerupine distribution: some localities for well-studied material: In Greenland, at Fiskenæsset. At Bjordam, near Kragerö, Norway. In Germany, from Waldheim, Saxony. From Mautia Hill, Tanzania. On the Bok se Puts Farm, Namaqualand, Cape Province, South Africa. Gem crystals from Itrongahy, near Betroka, and elsewhere in Madagascar. From gem gravels of the Matale, Ratnapura, and Embilipitiya districts, Sri Lanka. In the Harts and Strangways Ranges, Northern Territory, Australia. At Lac Ste-Marie, Quebec, Canada.
 

Kornerupine gems for sale:

We have not photographed the Kornerupine gems. Please check back soon.