How can you describe a mineral that sparkles, breaks into thin sheets, and has a measure of 9 on the hardness scale?
It is metallic, has cleavage, and can be easily scratched.
It is non-metallic, has cleavage, and can be scratched by a nail.
It is metallic, has cleavage, and can be scratched with special equipment.
It is non-metallic, does not have cleavage, and can be scratched with difficulty.