slate
A metamorphic stone that splits into sheets, used as facade sheets or shingles outside roof surfaces.
Pictured: 100 William Street
Slate is a metamorphic rock which splits very easily into sheets. It can be applied as a facade material in large sheets or, more commonly, in small overlapping shingles. It is only listed as a facade material when it appears on parts of the facade other than the roof. (Mansards, steeples, and other pitched roofs where slate occurs very frequently are not considered part of the facade).
Large sheets and overlapping small shingles are both included when they cover the facade. Piece size and overlap do not determine whether the stone is slate.
Location matters for this facade designation. Slate on a mansard, steeple, or other pitched roof is a roof covering even when that roof surface is visible alongside a wall.
slate Photos
Related definitions
-
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. -
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. -
tuff
A relatively soft volcanic rock made from consolidated erupted material, used as a textured natural facade stone.