Stalagmites
Domed calcite formations built up from mineral-rich water that deposits the dissolved mineral on the floor of caves
Size: 21cm
Stalagtite
Calcium carbonate-rich percolating groundwater precipitate as icicle-like forms of calcite from the roof of cave
Size: 20cm
Inside a Stalagmite
The evaporation of lime-bearing waters dripping into caves produces stalactites, which grow downward from the roof of a cave, and stalagmites, which grow upward from the floor. Both build up a layer at a time, and resemble tree rings in a cross section. A difference in mineral content on deposition causes color banding.
Size: 70cm
Travertine
Compact calcium carbonate deposit precipitated from warm water springs in hydrothermal systems
Size: 10cm
Tufa
Highly porous CaCO3 deposit with a spongy texture, precipitated from cool fresh spring water
Size: 10cm
Siliceous Sinter
Deposit of silica through precipitation from hot spring and geysers
Size: 10cm
Tufa
Calcareous sinter formed from precipitating water that traps in organic matter, such as leaves, moss and algae
Size: 15cm