thumb|upright|Calthemite straw stalactite growing from the concrete ceiling of an undercover car-park thumb|upright|Calthemite straw stalactites, the rightmost example demonstrating bending due to the direction of air currents during its formation
thumb|upright|Calthemite straw stalactite growing from the concrete ceiling of an undercover car-park thumb|upright|Calthemite straw stalactites, the rightmost example demonstrating bending due to the direction of air currents during its formation
Calthemite is a secondary deposit, derived from concrete, lime, mortar or other calcareous material outside the cave environment. Calthemites grow on or under man-made structures and mimic the shapes and forms of cave speleothems, such as stalactites, stalagmites, flowstone etc. Calthemite is derived from the Latin calx (genitive calcis) "lime" + Latin 2) from the surrounding air facilitates the reactions to deposit calcium carbonate as a secondary deposit. CO2 is the reactant (diffuses into solution) as opposed to speleothem chemistry where CO2 is the product (degassed from solution). It is most likely that the majority of calcium carbonate (CaCO3) creating calthemites in shapes which, mimicking speleothems, is precipitated from solution as calcite as opposed to the other, less stable, polymorphs of aragonite and vaterite.
Discovered by embedding cosine similarity (sentence-transformers MiniLM, 384-dim).