Question: Describe the strangest rock you found.

that’s a good question and quite difficult to answer I must say. I mostly look at sediments, so things like sand and clay for example, which are not really strange of course. However, there is also a kind of sediment that is formed under very special circumstances and can appear in many different ways, and this is gypsum! Gypsum you might know as something you use as a construction material, but it is also found in nature. It forms at places where sea or lake gets saltier and saltier (for example because the water evaporates) until it gets so salt that certain minerals (also called salts) have such high concentration that they will form gypsum crystals and sink to the floor. If this happens enough, a big layer of gypsum will form. Maybe you have read my profile page and you have seen that this actually happened in the Mediterranean sea 6 million years ago. The gypsum that formed then we can still find today, in southern Spain for example. The have big crystals that grow in all different directions, there they are partly white, partly colorless and feel a bit funny..smooth and hard at the same time, difficult to describe. They can come in many different structures (try to google ‘gypsum rocks’ and look at the differences!) but are all from the same material, and as I said, they are formed under very special conditions. So i would say they are one of the strangest rocks i found.

And what about you? have you ever seen any very strange of interesting rocks? if so, please tell me!