2.7" Calcite and Apophyllite on Orange Heulandite - India

This is a unique association of colorless, tabular apophyllite crystals and a large calcite crystal, over a bed of orange heulandite crystals that encrust the entire cavity. This gorgeous mineral association formed within a basalt pocket that was collected from Maharashtra, India.

Comes with an acrylic display stand.

This specimen comes from the Deccan Traps (a large igneous province and one of the largest volcanic features on earth) in the Pune Province of India. In the course of quarrying for other materials or digging wells sometimes large pockets of zeolites and other minerals are unearthed in the volcanic rock.

Apophyllite while not a zeolite itself is almost always found associated with zeolites in the same pockets. It has two crystal habits, a rectangular prism capped by a steep four sided pyramid or a pseudo-cubic structure. While not a well known mineral to the general public it is popular among mineral collectors due to it's pastel colors and beautiful crystal formations.

Calcite, CaCO3, is a carbonate mineral and the most stable polymorph of calcium carbonate. The other polymorphs are the minerals aragonite and vaterite. Calcite crystals are trigonal-rhombohedral, though actual calcite rhombohedra are rare as natural crystals. However, they show a remarkable variety of habits including acute to obtuse rhombohedra, tabular forms, and prisms. Calcite exhibits several twinning types adding to the variety of observed forms. It may occur as fibrous, granular, lamellar, or compact. Cleavage is usually in three directions parallel to the rhombohedron form.

Heulandite is a mineral of the zeolite group that also fits within the silicate and tectosilicates groups. It has the general chemical formula (Ca,Na)2-3Al3(Al,Si)2Si13O36 · 12H2O, however the calcium and sodium can be subsituted by potassium, barium and strontium ions. Heulandite crystals will often form as distinctive tabular, radiating crystals with a vitreous luster, of which can display a variety of colors including white, green, brown, orange, red, pink, yellow, grey and black.
FOR SALE
$135
DETAILS
SPECIES
Calcite, Apophyllite & Heulandite
LOCATION
Maharashtra, India
SIZE
2.7 x 2.5"
CATEGORY
ITEM
#176832