Okenite

Okenite is a hydrated calcium silicate mineral (CaSi₂O₅·2H₂O) that grows as fine, hair-like fibers bundled into soft white spheres resembling cotton balls. Okenite forms as a secondary mineral in basalt cavities (vesicles), deposited by hydrothermal fluids at relatively low temperatures (below 200°C). It grows as extremely fine, hair-like crystal fibers that bundle together into soft, fuzzy spherical aggregates resembling cotton balls or snowballs.

The most spectacular specimens come from India's Deccan Traps, a massive basaltic lava province covering much of western India. As these ancient lavas cooled, gas bubbles were trapped, creating cavities. Over millions of years, hot groundwater circulated through these cavities, depositing zeolite minerals and okenite.

Okenite often grows alongside gyrolite, apophyllite, and various zeolites, creating stunning miniature crystal gardens within basalt geodes. The delicate fiber aggregates form last in the mineral sequence, sitting on top of earlier-formed minerals.

Okenite's distinctive cotton-ball appearance is unmistakable. The white, fuzzy spherical aggregates of extremely fine crystal fibers look exactly like small snowballs or cotton balls sitting in basalt cavities. No other mineral forms quite like this.

Distinguish from mesolite (straight needle-like crystals rather than fuzzy balls), thomsonite (more compact, radiating crystals), and actual cotton or synthetic fibers (okenite is a mineral and won't burn like organic fibers). Handle with extreme care: the delicate fibers are easily damaged.