A cinder is a fragment of cooled pyroclastic material (lava or magma). Cinders are either intrusive igneous (magma cooled inside the earth) or extrusive igneous (lava cooled outside of the earth). Cinders are similar to pumice, which has so many cavities and is such low-density that it can float on water. Pumice or cinders are used in soap, xeriscaping, mulch, and rock gardens. Pyroclastic rocks or pyroclastics (derived from the Greek πῦρ, meaning fire, and κλαστός, meaning broken) are debris thrown from volcanoes during an eruption. ... Look up lava, Aa, pahoehoe in Wiktionary, the free dictionary. ... Magma is molten rock located beneath the surface of the Earth (or any other terrestrial planet), and which often collects in a magma chamber. ... Volcanic rock on North America Plutonic rock on North America Igneous rocks (etymology from latin ignis, fire) are rocks formed by solidification of cooled magma (molten rock), with or without crystallization, either below the surface as intrusive (plutonic) rocks or on the surface as extrusive (volcanic) rocks. ... Specimen of highly porous pumice from Teide volcano on Tenerife, Canary Islands. ... Specimen of highly porous pumice from Teide volcano on Tenerife, Canary Islands. ... A collection of decorative soaps used for human hygiene purposes. ... Xeriscape symbol Xeriscaping refers to landscaping in ways that do not require supplemental irrigation. ... In agriculture and gardening, mulch is a protective cover placed over the soil, primarily to modify the effects of the local climate. ... A rock garden, also known as a rockery or an alpine garden, is a type of garden that features extensive use of rocks or stones, along with plants native to rocky or alpine environments. ...

Volcanic eruptions such as this one can create cinders.

Wikipedia does not have an article with this exact name. ... Wikipedia does not have an article with this exact name. ...

Characteristics

The following geologic characteristics define a cinder: This article includes a list of works cited but its sources remain unclear because it lacks in-text citations. ...

• Uncemented
• Vitric
• Having bubble-like cavities, called vesicles
• Measuring not less than 2.0 millimeters in at least one dimension
• Apparent specific gravity between 1.0 and 2.0

Typical cinders are red or black in color. In Geology, a vesicle is a small enclosed cavity found in some volcanic rock--such as basalt--formed by the entrapment of gas bubbles as the material solidifies. ... Relative density (also known as specific gravity) is a measure of the density of a material. ...

Uses

Cinders have been used on track surfaces and roads to provide additional traction in winter conditions. Cinders are also popularly employed as inorganic mulch in xeriscaping, because of excellent drainage properties and resistance to erosion. In this context, they are referred to frequently with the synonym "lava rock". Xeriscape symbol Xeriscaping refers to landscaping in ways that do not require supplemental irrigation. ...

See also

• Cinder block
• Cinder cone
• Igneous rock
• Scoria
• Tephra