calmstone

Noun

colloquial countable uncountable

(colloquial) A sandstone, shale, or mudstone that forms in layers that are easily split into flagstones.

Japanese Meaning

（口語）層状に形成され、簡単にフラッグストーン（敷石）に割れる砂岩、頁岩または泥岩

The mason carefully selected pieces of calmstone to pave the courtyard because the layers split cleanly into flat slabs.

石工は中庭を舗装するために、層がきれいに割れて平らな板になるので、敷石に割れやすい砂岩の切れ端を慎重に選んだ。

Sense（1）

(colloquial) A sandstone, shale, or mudstone that forms in layers that are easily split into flagstones.

calmstones

（ plural ）