Natural stones are any type of stone that can be found on Earth’s continental crust, or the outermost layer of our planet. As the creation of these materials occurred over a slow and diversified process that ran over millions of years, it won’t come as a surprise the sheer volume of different types of stones that can be found in nature, spanning from precious ones showcased in a jewellery shop, to the polished ones we step on, on a daily basis.
The three main types of natural stone found on earth are igneous, sedimentary and metamorphic; this classification is dictated by how the stone was formed over the course of the years – or millennia – and gives us interesting and useful insights on the qualities of that specific natural stone.
Igneous stones were formed through the cooling and solidification of molten lava, or magma, a process that made them high density, low porosity and quite hardy materials. The most common types of igneous stones are granite, basalt, or bluestone, and porphyry.
As a testament of its creation process, Bluestone usually displays pitting in its texture as gas bubbles are trapped during the lava cooling process.
Examples of sedimentary stones include limestone, travertine and sandstone. This means they were formed over time with the accumulation and subsequent cementation of layers of mineral and organic particles.
As the components forming these stones can vary from sand and mud to coral or molluscs skeletons, their overall appearance can be quite varied – for instance, sandstone, as the name suggests, is mostly formed by sand size particles and has a characteristic amber-tan to peachy-red colour while limestone, mainly formed by molluscs skeletons, tends to have a light colour and display little nicks and shells through its texture.
