We’re Marble and Granite…of course we nuts about Granite! Here are just a few of the reasons why:
- Granite is the main constituent of the continental crust, and forms the core of the continents.
- Granite is a type of igneous, plutonic rock.‘ Igneous’ means it was formed by volcanic activity, while ‘plutonic’ indicates that this happened very deep below the Earth’s surface.
- Granite forms the world’s tallest cliff faces. These include the northwest face of Great Trango Tower in Pakistan, around 5,500 ft high, and the Ogre, Masherbrum, and K7 mountain faces. Many of the rock walls in the eastern fjords of Baffin Island, including Polar Sun Spire (around 4,700-5,000 ft) are also made of granite, as are Ruth Gorge in Alaska, the Mont Blanc massif, the Bugaboos of Canada, and the Fitzroy and Paine groups in Patagonia.
- All the granite we can see came from between 1 and 20 miles below the earth’s surface.
- The word granite comes from the Latin word granum, meaning ‘grain’ – probably due to its granular appearance, caused as molten rock cools beneath the Earth’s surface and solidifies as quartz, feldspar, mica and small quantities of other minerals. These minerals give granite its speckled look.
- Granite comes in a variety of colours. The different colour varieties are a consequence of the type of feldspar in the sample. Milky white granite contains plagioclase feldspar; pink granite contains pink or reddish alkali feldspar; grey granite contains white alkali feldspars; yellow, green and red granite all contain different shades of alkali feldspar.
- Granite crystals vary in size. This variation is caused by the rate of cooling during its formation. Coarser granite occurs when the molten rock has cooled more slowly.
- Granite is far more durable and stain resistant than limestone, sandstone or marble. These are the qualities that make it ideal worktop material.
- The third highest mountain in the world, Kangchenjunga, is made of granite. It’s 28,169 ft high. It’s part of a 2.5 mile-thick sheet of light-coloured granite formed deep in the thickened crust of the Himalayas.
- There are many forms of rock similar to, and incorrectly called, granite. True granite must consist of at least 20% quartz and 35% orthoclase feldspar. No other minerals are required, but these percentage criteria must be met.
- Granite has a density of around 162 pounds per cubic foot, so it’s about two-and-a-half times heavier than the same volume of water.
- Granite is approximately 50% oxygen by weight.
- Curling stones are traditionally fashioned of Ailsa Craig granite. The first stones were made in the 1750s, with granite from Ailsa Craig in Scotland. 60-70% of the curling stones in use today are made from Ailsa Craig granite.
- Granite has been used as a building material for thousands of years, and Aberdeen is known as the Granite City because so many of its building are made from this material.
