Thundereggs look like regular rocks from the outside, but contain intricate and colorful mineral patterns inside — often made ...

Mineral deposits can create markings that look like forests or mountains, and experts say each stone is distinctive. By Jill Newman When Tarun Adlakha displays a dendritic agate, with its finely ...

THIS exquisite image captures the astonishing internal structure of crazy lace agate, also known as Mexican agate. This section of the mineral is some 65 million years old. Agate is related to quartz ...

Picture this: you are wandering through the outdoors, and a glint of something unusual catches your eye. You look down and see a stone, but not just any stone. The colour or texture, or shape makes it ...

Roula Khalaf, Editor of the FT, selects her favourite stories in this weekly newsletter. Agate, chalcedony formed from layers of quartz and often treacle-brown, has long been associated with 1970s ...