tuff
A relatively soft volcanic rock made from consolidated erupted material, used as a textured natural facade stone.
Tuff is a relatively soft, highly textured rock formed from material ejected in a volcanic explosion. While its components vary, it generally consists of hardened volcanic ash mixed with various sediments released in the explosion along with pieces of molten rock or glass. Because of its easy workability it has been valuable since ancient times as a building material. Its variegated textures can make it aesthetically appealing as a cladding material.
The facade consists of the consolidated natural rock. Its fragments and ash can produce an uneven or varied texture across the cut surface.
Suevite can have a similar appearance, but forms through an impact rather than a volcanic eruption. Appearance alone does not establish the rock type.
Related definitions
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alabaster
A translucent gypsum or calcite stone, usually decorative indoors but occasionally used as a facade material. -
basalt
A dark, generally fine-grained igneous facade stone formed when lava cools and solidifies at the surface. -
gabbro
A dark, visibly grained intrusive igneous facade stone formed underground, here also including finer-grained diabase. -
granite
A hard, visibly grained igneous facade stone formed from magma cooling underground, used rough or polished. -
limestone
A sedimentary stone composed mainly of calcium carbonate, commonly used in natural stone building facades. -
marble
A brittle rock formed from calcite crystal and prized for its mottled patterns. -
quartz
A hard crystalline mineral occurring in many colors, normally clear or whitish when used on building facades. -
quartzite
A hard natural facade stone formed by the metamorphism and recrystallization of sandstone under heat and pressure. -
sandstone
A natural sedimentary facade stone made of cemented sand grains, commonly quartz, with varied colors and textures. -
serpentinite
A green metamorphic facade stone composed mainly of serpentine minerals, often selected for its color and pattern. -
slate
A metamorphic stone that splits into sheets, used as facade sheets or shingles outside roof surfaces. -
soapstone
A soft, talc-rich metamorphic rock with a slippery feel, used as a natural stone material on building facades. -
suevite
A composite rock formed in a meteor impact containing glass and fragments of rocks. -
travertine
A calcium-carbonate stone deposited from water, used as decorative natural stone and sometimes called travertine marble.