The Characteristics of Slate

Written by sarah clark
  • Share
  • Tweet
  • Share
  • Pin
  • Email
The Characteristics of Slate
Slate is a popular choice for shingles. (Jupiterimages/Photos.com/Getty Images)

Slate is a naturally-occurring metamorphic rock. It is valued for its ability to break into thin plates. Slate is mostly found in the Western Hemisphere. It is used for both decorative and utilitarian purposes. Slate comes in a wide range of colours that are determined by the minerals found within the stone.

Other People Are Reading

Mineral Properties

Slate is a metamorphic rock. It is derived from shale or mudstone that has experienced intense heat or pressure beneath the earth's surface. Slate is made up of parallel foliated plates. This gives it the ability to break smoothly and evenly along its cleavage. The hardness of rocks and minerals is measured using the Mohs scale, which ranges from one to 10 with one being the softest and 10 being the hardest. Slate ranks at 5.5 on the Mohs scale. It is hard enough to be able to scratch glass and steel.

Colours

The minerals it contains determine the colour of slate. Red slate is caused by hematite, green by chlorite, blue-grey by sericite, black by carbonaceous materials and yellowish-brown by limonite. Some types of slate are also mottled, streaked or spotted because of its mineral content. The cleavage surface of slate may have either a shiny or dull lustre. Cross fractures are typically dull. Slate is an opaque material that does not transmit any light.

Where It Is Found

Some of the most well known deposits of slate are found in the Western Hemisphere. Scotland and northern Wales have been supplying slate for roofing and paving since at least the 16th century AD. The early Celts may have had slate rooftops. The United States has a few substantial slate quarries along its eastern seaboard. There are also deposits found in its western and southern states. The Canadian provinces of Ontario, Nova Scotia and New Brunswick also have quarries. Brazil is famous for its "rusty slate," which contains the splashes of multiple colours on subtle grey.

Uses

Slate has historically been used for shingles and paving tiles. Slate also serves many decorative purposes. The rock makes plates, picture frames, coasters, trivets, beads and jewellery. Slate is also used to make fountains. The relatively flat and receptive surface of slate makes it fairly easy to write on with materials like chalk or charcoal. Slate has been used to make chalkboards for classrooms. Some artists use slate as a natural canvas.

Don't Miss

Filter:
  • All types
  • Articles
  • Slideshows
  • Videos
Sort:
  • Most relevant
  • Most popular
  • Most recent

No articles available

No slideshows available

No videos available

By using the eHow.co.uk site, you consent to the use of cookies. For more information, please see our Cookie policy.