1: percussion method: pick up the stone hand percussion, if the sound is loud and clear loud, to clarify the precise stone texture without Obscure, and vice versa easily rupture
2: Scratch: a knife or solid objects in the stone the appearance of scratches, if there is a white powder, to clarify such a slate texture
3: View of France: look at the stone with the naked eye appearance and texture of good slate appearance mineral impurities, the appearance of flat, filamentous texture, the color is purely natural.
4: Chemical method: 10% dilute hydrochloric acid drop in the stone, if the vesicles emerge and accompanying smoke is to clarify high calcium stone, slate easily erosion and weathering.
Four kinds brief way only primary detection, if the demand to further investigate the quality of the stone prestige professional testing organizations need to specific laboratory.