History of Stone by JW Smith

Stone is a natural solid formation of one or many minerals that came from the same liquid and gas minerals that formed the earth. The Earth developed as a massive body of gas and liquid minerals that slowly cooled and condensed to a solid core. Through pressure, the Earth’s crust began to form and heavy minerals were forced down to the core of the Earth where they were trapped. As the crust got thicker, it squeezed around the inner core which created intense pressure and heat from within the Earth. Crystals and other solid forms began to grow from the mineral vapours that were being released. As the Earth’s crust began to expand and erode, heat and pressure pushed the solid minerals up to the Earth’s surface which formed colossal rock beds. It took up to one-hundred million years to form some of these beds.

At more than 4.56 Billion years old granite is an igneous stone and is formed through volcanic material such as magma. Underneath the Earth’s surface, liquid magma cooled and solidified. Mineral gases and liquids penetrated into the stone and created new crystalline formations with various colours. Granite is primarily made of Quartz, Feldspar and Potassium and has a heavy crystalline and granular appearance with mineral grains. Granite is a hard stone, measuring 6-7 on the Measure of Hardness Scale (MOH).

Marble is a younger and softer metamorphic stone. Being only 3.1 billion years old, Marble is a re-crystallised limestone that formed when the limestone softened from heat and pressure and re-crystallised into marble where mineral changes occurred. The main consistency is calcium and dolomite. Mable comes in a range of colours and is usually heavily veined. Its hardness rates from 2.5 to 5 on the MOH Scale.

Slate is a fine grained metamorphic stone that is formed from clay, sedimentary rock shale, and sometimes quartz. Slate is usually black, grey, or green.

Limestone which consists mainly of calcite is a Sedimentary stone which comes from organic elements such as glaciers, rivers, wind, oceans, and plants, which are bonded through millions of years of heat and pressure. Limestone does not show much graining or crystalline structure. It has a smooth granular surface and varies in hardness. Some dense limestones can be polished. Common colours are black, grey, white, yellow or brown. Limestone is known to contain lime from sea water.

The majority of natural stone comes from quarries in Italy, Spain, Turkey, United States, Mexico, China, Taiwan, India, Greece, Canada, France, and Brazil.