Slate Origins

A history of welsh slate and it’s origins


Slate is a metamorphic rock – that is to say it is a rock born of another rock. This birth began some 500 million years ago……..Welsh Slate Quarry Workers

  • Muds and silts deposited in the welsh basin (a large sea area including what is now llanberis ) were slowly buried by other sediments and volcanic ash. This process caused the muds and silts to change.

  • The crushed muds and silts became hot and dry as all water was squeezed out of them, and gradually hardened into the rock known as slate.
  • For much of it’s 500 million year history, the slate has remained buried beneath the surface of the land. However, during the last 2 million years the land surface has been excavated by the power of glaciers during successive ice ages, exposing the slate visible today.
  • Slate is usually thought of as being black or grey, however different chemical reactions cause different minerals to occur in the rock producing colours such as blue, green and purple.
  • The minerals that make up slate are known as silicates and aluminium silicates or micas. It is the micas that produce the most characteristic feature of slate – that is, it’s ability to split into flat sheets along the grain of these micas (slaty cleavage). This feature makes slate ideal for roofing tiles and for a great many uses including art and craft.

By choosing welsh slate for your house name or number plaque:


  • Slate will not rot & will last forever
  • Welsh slate is the best quality in the world
  • It is a natural product
  • slate name plaque is very distinctive


  • By having a slate name or number plaque on your house
  • Whatever the type of property, terraced or detached your house becomes individual

Welsh Slate Name Plaque

  • A slate plaque is distinctive
  • It gives you a sense of pride
  • The convenience of slate is that it is weatherproof & requires no maintenance
  • By having a slate plaque it is keeping alive a part of welsh heritage.

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