Re: How Can You Scratch A Sapphire Crystal? While I have never actually heard of this happening, I find it plausible. Looking at the Mohs hardness scale (which is a relative scale, not absolute: IE: a 2 is not necessarily TWICE as hard as a 1), we find that Sapphire is a 9, and diamond is a 10. It's generally assumed that any substance with a higher number can put a scratch on anything with a lower number. What catches my attention is that silicon carbide is a 9.4 or so. This material is widely used in abrasives, such as sandpaper.
noun. The definition of conventional wisdom refers to something that is widely accepted as true or correct or proper. An example of conventional wisdom is the idea that if you work hard you will succeed.ords near conventional wisdom in the dictionary. 1  conventional-wars. 2  conventional-weapon. 3  conventional-weaponry. 4  conventional-weapons. 5  conventional wisdom. 6  conventionalise. 7  conventionalised. 8  conventionalises. 9  conventionalising. 10  conventionalism.
Testing makes perfect, finds memory retrieval research. Conventional wisdom holds that if you want to learn something, study, study, study. In Science (Vol. 319, No. 5,865), a team of psychologists reports that students who were repeatedly tested on material significantly outperformed those who repeatedly studied it.