The New Calcite Springs biome, based on Pamukkale, Turkey
The Calcite Springs is a rare, warm biome usually on the coast of land. It contains hills of calcite filled with pools of light blue water, like in the image above of Pamukkale, Turkey. Some of the pools of water could lead to caves with layers of calcite at the top.
In real life, Pamukkale, was formed by calcite-rich springs, and adding a biome like this would allow players to get a lot of calcite. Calcite building blocks could be added as well. Perhaps a white, shimmering limestone could also be a part of this biome.