NESQUEHONITE

    Class : Carbonates, nitrates, borates
    Subclass : Hydrated carbonates
    Crystal system : Monoclinic
    Chemistry : MgCO3 3H2O
    Rarity : Rare

Nesquehonite is a rare hydrated carbonate found in magnesium environments. It is first of all a serpentinite alteration mineral, accidentally present in certain coal mines and in hot spring deposits. It owes its name to its place of discovery : the Nesquehoning coal mine (Pennsylvania, USA). Nesquehonite generally occurs in radiated tufts of acicular crystals, sometimes as striated prismatic crystals, felted or botryoidal aggregates, or radiated, colorless or white encrustations. Nesquehonite occurs commonly in pseudomorphs after landsfordite, another magnesium carbonate that also appears to form under current atmospheric conditions.

Main photo : Nesquehonite from Plavno mine, Czech Republic © Bohuslav Bures

Nesquehonite from Nesquehoning, Pennsylvania, USA © Jolyon Ralph
Nesquehonite from Brosso Mine, Italy © Flavio Giuseppe Taricco
Nesquehonite from Sounion Mine, Laurion, Greece © Elmar Lackner
Nesquehonite from Monte dei Tre Abati, Italy © Fabio Marina

Nesquehonite in the World

Nesquehonite forms the base of landsfordite stalactite in the Nesquehoning coal mine, Pennsylvania, its type locality. It is also found filling cracks in Italian serpentinites, notably at the Franscia asbestos mine (Val Malenco, Lombardy), and at Lillaz (Aosta Valley).

Nesquehonite in France

The most beautiful nesquehonite crystals, reaching 5 cm, come from the La Mure mine (Isère).

Twinning

No twins known for this mineral species.

Fakes and treatments

No fakes recorded for this mineral species.


Hardness : 2.5
Density : 1.82 to 1.85
Fracture : Fibrous
Streak : White

TP : Translucent to transparent
RI : 1.412 to 1.526
Birefringence : 0.114
Optical character : Biaxial -
Pleochroism : None
Fluorescence : None

Solubility : Hydrochloric acid, water

Magnetism : NoneRadioactivity : None