All of the following are synthetic sharpening stone except:
Silicon carbide
Alumina
Arkansas
Diamond
Stone type can come in natural or synthetic form:

Natural-Arkansas (preferred)
Synthetic:
	
India stone
Ceramic stone
Composition stone
Diamond
Alumina
Silicon carbide



Nisha Garg, Amit Garg. Textbook of Operative Dentistry.  Edition 3. Page:97