A sphere has reflection symmetry across any plane through its center.
The law of conservation of matter states that matter cannot be created nor destroyed. It can only be transformed from one form to another. To state an example where this is shown, let's say a piece of paper is burning. Not having a scientific background, you would say that the matter is being destroyed. But in reality, the paper is simple being transformed to ash, carbon dioxide, and water vapor. Overall, the total mass would still remain the same.
He performed a streak test, in which a piece of the mineral is rubbed across a piece of unglazed porcelain in order to determine the color of the mineral in powdered form.
