Underground Journey spelled in a cave photo
Cave Pearls is a spherical Speleothem found in shallow puddles of solutional cave. Its shapes are spherical, elliptical, cubes, polygonals, etc., ranging from small sand grains to huge ones with a diameter of 20 cm.
At the center of the cave pearl is a nucleus, with various materials such as sand grains, Speleothem fragments, crab claws, snail shells, and earthenware fragments.
It is thought that the cave pearls grow in spherical shape because calcium carbonate crystallizes from the groundwater of solutional cave (calcium bicarbonate solution) and it accumulates evenly on the surface of the cave pearls (it does not seem to need to be rotated in water).
In addition, in order to grow while maintaining a spherical shape, it is necessary to have an environment where cave pearls constantly shake due to the flow of water flow and dripping water so that they do not adhere to the cave floor.
On the riverbed of the underground river in Gyokusendo Cave, there is also a cave bean stone that grows into the size of potatoes. It is difficult to confirm the material of the core when cut in half, and it looks like a cross-section of a lime algae ball.
In Gyokusendo Cave, we are conducting a man-made experiment of cave pearls in the tourist cave area. After a few years, you will notice the change in size.
