You can find these chunks of Basalt covered in bugs from different places in Scotland. Anywhere that you find a river or stream which crosses through areas of historical lava flow you will find this Basalt. It is cooled lava originally. The lava cooled slowly, allowing the air bubbles from the material to get stuck as they rose. Over the millennia, these bubbles infill with minerals and we get agate. This is not agate but the lava they come in.
Called galaxy stones because they look like space spotted with stars and planets, these are fascinating rocks which include mixed minerals. This Scottish galaxy stone has green, white, and pink vugs. It came from Ayrshire in 2022.