Tektites

Rounded tektites.

Tektites found in Australia are known as Australites. It is believed they formed 790,000 years ago due to a major meteorite impact in Southern Laos.

The key feature of some Australites is their button-like shapes. When they re-entered the atmosphere, the bottom of the glass pieces started to melt, pressure pushed the molten material upwards during the descent and created a ripple effect on the sides.