Image: <bdi><a href="https://www.wikidata.org/wiki/Q56247090" class="extiw" title="d:Q56247090"><span title="mineral collector and dealer">Robert M. Lavinsky</span></a></bdi> (CC BY-SA 3.0)
monocliniccommonSilicates (Zeolite Group)
Heulandite
(Ca,Na)2-3Al3(Al,Si)2Si13O36·12H2O
This specimen features pearlescent clusters of radiating, tabular heulandite crystals, exhibiting delicate light pinkish-orange to white hues.
Heulandite Physical Properties
Mohs Hardness
3.5Crystal System
monoclinicLuster
pearlyStreak Color
whiteCleavage
perfect on {010}Fracture
unevenSpecific Gravity
2.2Colors
white, pink, light orangeTransparency
transparentType Locality
Teigarhorn, Berufjördur, Suður-Múlasýsla, IcelandMineral Group
Silicates (Zeolite Group)Uses
collector, industrial (minor)Associated Minerals
stilbite, apophyllite, calcite, quartzRarity
commonGeological Context
Heulandite commonly forms in the amygdaloidal cavities of basaltic volcanic rocks through hydrothermal alteration, and can also be found in some metamorphic and sedimentary environments.
