Lustro Italiano > Stone Reference > Slate

Natural Slate


Summary

Description:Natural slate is a rock that forms through a natural process. Here is some information regarding natural slate.

Formation Process: Natural slate is a metamorphic rock that is created by the alteration of shale or mudstone by low-grade regional metamorphism.

Appearance: Slate forms in various colors including red, blue-gray, green, black, and yellowish-brown. Like other natural stone, slate's color is affected by the minerals it is composed of.

Composition: Natural slate is made up of a variety of minerals. For example, other minerals are what bind the silica particles together and form the stone.


Composition of Natural Slate

Slate is a natural stone that is composed mainly of the mineral quartz. It can contain other substances (such as iron oxide or alumina) as well but it is made up of mostly quartz. Here are some of the components than can be in slate:

  • SiO2 (Quartz)
  • Al2O3 (Alumina)
  • Fe2O3 (Iron Oxide)
  • Na2O (Soda)
  • K2O (Potash)
  • CaO (Lime)
  • MgO (Magnesia)
  • TiO2

Natural Slate Characteristics

Depending on the amount of and type of minerals in a given piece of slate, it can be a variety of appealing colors. The porosity of a particular stone can vary depending on the composition. Additionally, slate normally has a hardness of 5-6 on the Mohs scale of mineral hardness.

Applications and Uses

Slate is used for many applications and for a variety of purposes. For example, slate is a material that is used for:

  • Patios
  • Stairs
  • Roofing
  • Cladding
  • Flooring
  • Chalkboards
  • Billiards Tables
  • Landscaping & Hardscaping

Advantages of Natural Slate

One advantage to slate is that it has a unique look and adds character to a structure in which it is used. Additionally, slate, when used as a roofing material, is very durable and in a number of cases adds value to a home. This is because of the durability of the material. Natural slate is a very hard material and is not easily scratched or chipped.

Slate is also an advantage when it is used as a flooring material. Again, because of the durability of this stone, it can be installed once and last many years without needing replacement.

If you are considering radiant heating, slate can be a great choice. In fact, many natural stone surfaces are well-suited for radiant heat. Various types of radiant heating systems can be installed below slate floor tiles.

Since it is a natural material, slate is compatible with a number of other materials. The colors of slate also make it complimentary to a variety of other elements used in very unique designs. Slates are available in tans, greys, reds, beiges, and many other neutral colors.

Slate's Disadvantages

One drawback to using slate is that it is very porous. This is the case for all natural stone materials, slate included. Each natural stone is porous to a one degree or another. This means it has the potential for being susceptible to staining via liquid substances. Yet, there are ways to care for and maintain slate.

Natural slate is a heavy material and even the tiles are extremely heavy. If it is used in upstairs rooms or as a roofing material it is important that the structure is able to support the weight of the stone.

Additionally, when fabricating slate it is necessary to use a diamond blade that is made for cutting hard stone materials. Hence, finding tooling designed for effectively cutting very hard materials is a key to successfully working with slate in fabrication.

Slate Care and Maintenance

Caring for natural slate is simple. However, simple does not necessarily mean it is easy. One of the simplest ways to care for slate is to regularly seal it. Sealing natural stone can help protect it from staining that could occur from colored liquid that could get into the pores of the stone and discoloring it. Here are some practical steps that can be taken to care for and maintain natural slate.

One of the most effective ways to care for your slate surface is to clean up any spills immediately. This keeps the liquid from getting into the pores of the stone and creating a stain than will require a stain remover to clean up. In addition to reacting quickly to spills that occur it is recommended that owners of slate have a regular routine of cleaning and resealing natural slate surfaces.

  1. Make sure to initially seal slate countertop surfaces to make oil and water based spills easier to clean.
  2. Use a pH neutral cleaner on your slate surfaces. Acidic cleaners breakdown the sealer and allow stain causing liquids to penetrate the pores of the stone.
  3. Periodically use an impregnating sealer to renew the seal that was added right after installation.

By using the pH neutral stone cleaner and regularly reapplying stone sealer periodically, you can consistently maintain the appearance of your slate surfaces.

In conclusion, slate is a natural stone that can be used for a number of applications; including roofing and flooring among others. It offers advantages over other materials but like everything else, it is not the perfect material for every situation or application. The beauty and durability of slate though, may make it a good choice for a number of projects. And in certain design styles, it may even be the best fit.