Helictite

Helictite is a type of speleothem found in caves. It is characterized by thin, twisting, or branching mineral growths that can extend in any direction, including upward, rather than in a uniform downward or upward column as with stalactites or stalagmites. The shapes resemble twigs, threads, or miniature branches and are frequently translucent or pale in color.

Helictites form where mineral-rich water enters cave air and is drawn into minute capillary channels along rock surfaces. As the water slowly evaporates or degases CO2, minerals such as calcite or aragonite (and in some cases gypsum) are deposited in tiny amounts. The direction of growth is influenced by air currents, humidity, and microcracks, causing the structures to grow in irregular, spiraling, or threadlike forms rather than straight downward. Growth is slow and can occur over thousands of years.

Common in many carbonate caves around the world, helictites vary in size from a few millimeters to several centimeters. They are more fragile than other speleothems and can be damaged easily by touch or vibration. The term helictite is derived from Greek helix meaning 'coil' or 'spiral', reflecting their characteristic shapes. They are studied in cave science as indicators of microclimate conditions, but their fragile nature means they are treated with care in show caves.