2.1" Lustrous Apophyllite and Chabazite Crystals on Chalcedony - India

About Chabazite

Chabazite is an eye-catching mineral from the zeolite group, admired for its beautifully symmetrical crystal structure and pastel colors. Typically forming in rhombohedral or cubic-like crystals, chabazite often appears in hues of white, pink, orange, or light yellow. This mineral is primarily composed of hydrated calcium aluminum silicate, giving it a lightweight, porous structure that enables it to act as a natural ion-exchanger—a property commonly seen in zeolites.

Chabazite crystals have a vitreous to pearly luster, and their transparent to translucent appearance gives them an almost delicate, ethereal quality. With a hardness of about 4.5 to 5 on the Mohs scale, chabazite is moderately soft, making it suitable for display rather than wear. It typically forms in cavities within volcanic rocks like basalt and andesite, where it grows alongside other zeolite minerals such as heulandite, stilbite, and analcime. Some of the finest chabazite specimens come from Iceland, Italy, and India, renowned for their vivid color and well-formed crystals.

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 western 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 its pastel colors and beautiful crystal formations.