Stalactite. A cylindrical or conical deposit of calcite hanging from the roof of a cavern, formed by evaporation of water droplets containing calcium carbonate.
Stalagmite. Columns or ridges of calcite rising from the floor of a cavern, formed by water containing calcium carbonate dripping from a [stalactite].
Stock. A mass of igneous intrusive rock that covers less than 40 square miles, has steep sides, and extends to an unknown depth.
Tennantite. A metallic gray mineral that contains copper, iron, and arsenic, and is an ore of copper.
Tetrahedrite. A brittle, dark gray to black, metallic mineral containing copper, iron, zinc, and silver.
Trilobite. One of a primitive group of extinct marine crustaceans, related to crabs and lobsters, having segmented bodies divided by longitudinal grooves into three lobes.
Unconformity. A surface separating layers of rock, formed by a period of nondeposition or erosion.
Vein. A crack or fissure filled with mineral material, often with valuable ore minerals.
SUGGESTED READING
There are thousands of scientific articles and books on Colorado geology, and many new ones appear each year. Following is a selection of books and booklets which we believe will be most useful and interesting in extending your knowledge of the state’s geology.