Mineral description : Ludwigite

Black fibric aggregates of ludwigite in calcite.
From Tallgruvan.

Mineral class Borates : Kotoite - Ludwigite group.

Chemical formula (Mg,Fe)₂FeBO₅

Crystal system Orthorhombic.

Habitus Fibrous, radial, massive fibrous or as small prismatic crystals.

Cleavage [001] perfect. Fracture brittle, conchoidal.

Hardness 5.5

Density 3.7-4, average 3.86

Color Bluish gray, grayish black to black or greenish black.

Streak Greenish black.

Luster Silky, opaque.

Description

Occurance

Associates

Notes Hard to see, but gives the magnetite ore a dull luster when Ludwigite is present.
No luminescens.
Named after the Austrian chemist E. Ludwig (1842-1915)

Locations A rare mineral in scandinavia.
Sweden :

Tallgruvan, Norberg, Västmanland. Occurs as fibric aggregates or as small prisms. With magnetite in serpentine.
Norway : No known localities.
Finland : No known localities.

To borates index.
Mineral group index.
Main index.

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Last changed : 2001-01-30

Mineral class	Borates : Kotoite - Ludwigite group.
Chemical formula	(Mg,Fe)₂FeBO₅
Crystal system	Orthorhombic.
Habitus	Fibrous, radial, massive fibrous or as small prismatic crystals.
Cleavage	[001] perfect. Fracture brittle, conchoidal.
Hardness	5.5
Density	3.7-4, average 3.86
Color	Bluish gray, grayish black to black or greenish black.
Streak	Greenish black.
Luster	Silky, opaque.
Description
Occurance
Associates
Notes	Hard to see, but gives the magnetite ore a dull luster when Ludwigite is present. No luminescens. Named after the Austrian chemist E. Ludwig (1842-1915)
Locations	A rare mineral in scandinavia. Sweden : Tallgruvan, Norberg, Västmanland. Occurs as fibric aggregates or as small prisms. With magnetite in serpentine. Norway : No known localities. Finland : No known localities.