I need a little help identifying this rock. It was found somewhere in the Sahara Desert. It is very hard and leaves a beige streak on a steel file (might be the concretized dirt covering it). The polished window shows little black specks scattered around. There are also some tiny shiny specks which the camera doesn't capture. No discernable layering. It is non-magnetic. Measures around 3cm long (1 1/4").
I've never seen a rock like this before, would appreciate some help identifying it!