The original planting that Kimura did was made of Kurami Stone. It is a common stone in Japan in the building trade and for hobbies. It is strong and is a mixture of natural volcanic ground stone mixed with a hardener and drenched into wrapped weave. It is textured while wet and the coloring is in the stone when made, much like Corion by Dupont is made here. There are natural bowl type Kurami stones that are actually from volcanoes. Those are rare!!!! Like diamonds!
The word Kurami in Japanese means "wrapped". In the original, Kimura notched the two pieces and then put them together like interlocking your fingers with two peace signs.
The whole thing was shown step by step in Bonsai Today like twenty or more years ago. Kurami stone used in bonsai is not rare or natural. Someone on facebook, I think Kaede Bonsai is selling kurami stone waterpool stones with a bamboo water dipper for like $450.00. The text says rare....right!