Perhaps you’ve stood at the steps of St Mary’s Cathedral, or you’ve marvelled at the smoothness of the sandstone blocks that make up the old arts buildings at the University of Melbourne or University of Sydney. Perhaps you’ve stood at the foot of Wave Rock or Uluru and witnessed the incredible bands trapped in the stone. Sandstone has a rich warmth to it whether it’s a white, brown, gold, cream or pink shade, and often comes decorated by stunning natural bands. But have you ever wondered how sandstone acquires its bands and colours? Gosford Quarries has the answer. Read on to learn more.
How sandstone is made
As the name suggests, sandstone is stone formed from sand due to high pressure and heat as the sand subsides into the earth’s crust. It is composed of varying amounts of feldspar, quartz, and even silt and clay. As the earth’s crust moves, the sandstone may be pushed back up to the surface, where wind and water begins wearing it back down into sand before it’s pushed once more back into the crust to become sandstone again (this cycle takes around 200 million years
But how does it get its stunning colouring and bands?
The answer is iron oxidisation and slow sand depositing. Sandstone is made primarily from quartz surrounded by iron oxides. The more iron oxides are present, the more colour in the sand – as it quite literally rusts. White sandstone has little or no iron oxides present.
For the bands to form, vast amounts of sand are deposited in fine layers over millennia. These layers receive their colouring and width depending on the minerals they are comprised of. As the layers are pushed into the earth’s crust, these bands can become folded, creating even more intricate patterns. Sandstone then, is a physical record of the wearing down of stone millions of years ago.
Australia’s leading sandstone provider
Are you considering sandstone for your property? Trust Gosford Quarries, the providers of the finest sandstone available in Australia. We offer Brown, Pink, Grey, gold, cream and white sandstone in stunning banded and un-banded varieties. Reach out to our team to discuss your project.