Mineral description : Hemimorphite

Hemimorphite on green smithsonite. From Mexico.
Size 7x4x3.5 cm. (description) Hemimorphite crystals on limonite. From Mapimi, Mexico.
Size 7x5x3.5 cm. (description) Bluish hemimorphite. From Sa Duchessa, Sardinia, Italy.
Size 4x3x2.5 cm. (description)

Mineral class Silicates : Sorosilicates : Hemimorphite group.

Chemical formula Zn₄(OH)₂/Si₂O₇)^.H₂O

Crystal system Orthorhombic

Habitus Thin tabular crystals with striations along the crystal. Crystal terminations are different at each end (hemimorphic).
Also common as fibric radial crusts and botryoidal masses.

Cleavage Perfect in one direction, fracture conchoidal to subconchoidal.

Hardness 4.5 - 5

Density 3.4 - 3.5

Color Colorless, bluish green, white, yellow or brown.

Streak Colorless.

Luster Vitreous to silky, transparent to translucent.

Description A secondary zinc mineral formed by weathering of other zinc minerals.

Occurance In the oxidation zone of zinc veins.

Associates Sphalerite, smithsonite, malachite, azurite, cerussite and anglesite.

Notes Named after it's crystal form with differing ends (hemimorphic).
Type Localit: Baita (Rézbánya), Bihor, Romania.
A name that was used earlier was "calamine", but it is now used on another mineral.
Gives off water when heated in a closed test tube.
Soluble in acids with gelatinization.
Fuses only at a high temperature.
Strongly pyroelectric and piezoelectric.

Localities A rare mineral in Scandinavia.
Sweden :

Garpenberg, Dalarna. In the "mullmalm" ore, together with other secondary lead and zinc minerals.

Norway :

Konnerud, Grua.
Skjerpemyr, Grua. As white radiating balls 1-3 cm in size. Also as crystals up to 3 cm in cavities.
In contact zones around the Drammen granite, Konnerudkollen and Damåsen.

Finland : (Sorry if the names are messed up, but I don't speak Finnish)

Träskböle pegmatite, Perniö.
Korsnäs, Wasa.

To silicate index.
Mineral group index.
Main index.

If you have some questions, suggestions or comments you are welcome to write me a line or two.

axelsson@acc.umu.se

To my homepage.
Last changed : 2001-11-01

Mineral class	Silicates : Sorosilicates : Hemimorphite group.
Chemical formula	Zn₄(OH)₂/Si₂O₇)^.H₂O
Crystal system	Orthorhombic
Habitus	Thin tabular crystals with striations along the crystal. Crystal terminations are different at each end (hemimorphic). Also common as fibric radial crusts and botryoidal masses.
Cleavage	Perfect in one direction, fracture conchoidal to subconchoidal.
Hardness	4.5 - 5
Density	3.4 - 3.5
Color	Colorless, bluish green, white, yellow or brown.
Streak	Colorless.
Luster	Vitreous to silky, transparent to translucent.
Description	A secondary zinc mineral formed by weathering of other zinc minerals.
Occurance	In the oxidation zone of zinc veins.
Associates	Sphalerite, smithsonite, malachite, azurite, cerussite and anglesite.
Notes	Named after it's crystal form with differing ends (hemimorphic). Type Localit: Baita (Rézbánya), Bihor, Romania. A name that was used earlier was "calamine", but it is now used on another mineral. Gives off water when heated in a closed test tube. Soluble in acids with gelatinization. Fuses only at a high temperature. Strongly pyroelectric and piezoelectric.
Localities	A rare mineral in Scandinavia. Sweden : Garpenberg, Dalarna. In the "mullmalm" ore, together with other secondary lead and zinc minerals. Norway : Konnerud, Grua. Skjerpemyr, Grua. As white radiating balls 1-3 cm in size. Also as crystals up to 3 cm in cavities. In contact zones around the Drammen granite, Konnerudkollen and Damåsen. Finland : (Sorry if the names are messed up, but I don't speak Finnish) Träskböle pegmatite, Perniö. Korsnäs, Wasa.