rock mass; boulder; block of rock
Refers to a large, solid piece of rock, often in geological or descriptive contexts.
A huge rock mass had fallen onto the mountain path.
Many granite boulders can be seen in this area.
volcanic block
Compound of 岩 (iwa, 'rock') and 塊 (katamari, 'lump' or 'mass'), using the on'yomi readings gan and kai. The exact historical derivation is uncertain, but the word follows a common Sino-Japanese compounding pattern.