The word 'calcareous' is correct and can be used in written English.
Calcareous is an adjective that means “containing or consisting of calcium carbonate or calcium,” and is commonly used to describe rocks, shells, and soils. For example, you could say "The soil in this region is mostly calcareous, making it difficult to grow certain crops."
Most calcareous sponges are white.
Compare calcareous sponge; horny sponge.
The cavities in calcareous sinter are partly due to the decay of mosses and other vegetable structures that have assisted in its precipitation.
The calcareous plateaus of Laon, Soissons, and Valois rise to the east.
The oozes are subdivided first into calcareous oozes (containing skeletons made of calcium carbonate) and siliceous oozes (containing skeletons made of silica) and then are divided again according to the predominant skeleton type.
The Harz Mountains show a more calcareous Lower Devonian section.
Latvia's soils are predominantly podzolic, though calcareous soils characterize the Semigallia (Zemgale) Plain, located just east of the Eastern Kurzeme Uplands.
In certain species, additional layers of membranous material are deposited around the embryo, but the calcareous (calcium-containing) shell does not form.
Examination of the oxygen preserved in polar ice and calcareous fossil shells has revealed the climatic evolution of the recent geologic past.
Cystoid, any member of an extinct class (Cystoidea) of primitive echinoderms (animals with a hard, calcareous external skeleton, related to the modern sea lily and starfish) that first appeared during the Middle Ordovician Epoch and persisted into the Late Devonian Epoch (the Ordovician Period began about 488 million years ago, and the Devonian Period ended 359 million years ago).
In many specialized genera the crura support calcareous loops or spires (brachidia), the inner skeleton of the lophophore.
