Volcanic tuff refers to a rock formed from volcanic ash and fragments that have been compacted and hardened over time. It is a type of sedimentary rock, commonly found near volcanic areas. Full definition
Coarse chunks of volcanic tuff and brick compose about 45 - to -55-percent (by volume) of the concrete. (sciencedaily.com)
Ethiopian King Gebre Mesqel Lalibela ensured his name would always be uttered with awe, when he commissioned 11 interconnected monolithic churches and two chapels to be carved out of red volcanic tuff in the 12th century at his birthplace in the northern reaches of his... (eagerjourneys.com)
Water - based rain dates back to at least the late Archaean Eon: Researchers have found fossilized raindrop imprints in 2.7 billion - year - old volcanic tuff in South Africa. (discovermagazine.com)