is a fine grained metamorphic stone formed from clay mud; composed of
sediments of decomposed stone and organic matter that has been hardened by
heat and pressure. Since the geological process varies greatly, slates range
quite a bit in hardness and porosity.
Slate characteristics vary with source. It may be black, green or mottled
and is relatively dense. Many imported slates are available today with wide
ranging physical characteristics and overall suitability. The stone differs
in density, tensile strength, absorbency and abrasion resistance.
- Composition: Muscovite, chlorite, kaolinite, micas, quartz
and other accessory minerals (wide variation in composition).
- Hardness: Soft - easily scratched. They can also be as hard
and dense as granite
- Absorption: Low - medium oil, water other liquids
- Weathering characteristics: Due to the wide ranges of slate, this
stone has wide ranges of weathering. Cleft planes provides permeability
for water penetration resulting in spalling and flaking. Slates that
have a high kaolinite content (a clay) display accelerated rate of
deterioration in wet environments
- Tendencies: Absorbs oils and liquids...Softer/medium
varieties scratches easily.
- Colors: Colors vary widely
- Finish: Different finishes such as acrylic, wax, natural
cleft, honed etc. Some types may be flamed.
: Chemical Properties
| Physical Properties
| Installing Slate Tile
| Slate Cleaning
| Slate Cutting
| Slate Sealer