The Secret of the Sun Stone

The otoliths have strange mineral formations made out of calcium carbonate. This is the same compound that makes up the bulk of the shells of sea creatures and pearls, but also chalk. It's used in tons of human technology - for example, agricultural limea make chalk for a blackboard,. But i also found one total off topic connection that i couldn't bear not to mention: there's one common, stable crystal form of calcium carbonates known as calcite. And there is one very strange and beautiful form of calcite known as iceland spar, which is a transparent rock. I think we talking about iceland because this crystal can be used to detect the direction of the