Fragments of asteroids regularly land on Earth as meteorites. If you examine such a find, you can see that it comprises millimetre-sized round stones, known as chondrules. These small particles are ...

Perfect circles of stones cover the ground in parts of Alaska and the Norwegian islands of Spitsbergen. Elsewhere in the far north, stones form other striking patterns on the ground: polygons, stripes ...

Kidney stones are solid deposits of minerals that can form in the kidneys, also known as renal calculi. They can be made up of various types of crystals, with the most abundant crystal determining the ...