Although at least 20 types of rocks have been identified at the site, Stonehenge is made from two primary types of stone: sarsen sandstone and bluestone, with the stones forming the external wall of the circle in Stonehenge being made from the former. Sarsen sandstone is around 60 million years old and is essentially silicified sandstone that is much like the sandstone that is found about 19 miles to the north of the world-famous monument.Know More
The pie-shaped structures for which Stonehenge is so readily known for are made from sarsen sandstone. The largest of these weighs an estimated 40 tons, which is the weight of a cement truck that's fully loaded. The size of this stone and others has led to many theories about how the stones arrived at the location in the first place.
The smaller of the stones at Stonehenge are bluestones, and although they are smaller than the sarsens, some are still massive, weighing up to an estimated 4 tons. They are foreign to the area, leading to even more speculation as to how they arrived there.
There are other types of rock at the location, including gneiss, schist, limestone and greenstone, along with some unidentified sandstones. The "Altar" at Stonehenge is from a foreign sandstone of unknown origin.Learn more about Prehistory
The earliest tools of cavemen, dating back millions of years, were made of bone, stone and wood. The handaxe was the first major tool developed by early humans, consisting simply of a sharpened stone held in the hand and used to chop and pierce.Full Answer >
Most prehistoric paints were made from minerals like hematite, iron and limonite that oxidize and combine to form a pigment called ochre. Charcoal, burned bones and ground calcite were also used. These materials were mixed with animal fat or other binding materials to form the paint.Full Answer >
During the Precambrian Era, single-celled organisms, bacteria, microbes and some multi-cellular organisms existed. The Precambrian Era is split into the Hadean, Archaean and Proterozoic eons.Full Answer >
Rock salt is made of a 1:1 ratio of sodium to chlorine. Rock salt's chemical formula is NaCl, which means that one molecule of rock salt is composed of one atom of sodium (Na) and one atom of chlorine (Cl).Full Answer >