Mohs scale of mineral hardness incorporates additional substances that may fall between levels: Comparison between hardness (Mohs) and hardness (Vickers): Mohs scale of mineral hardness The Mohs scale of mineral hardness is a qualitative ordinal scale characterizing scratch resistance of various minerals through the ability of harder material to scratch softer material. Created in 1812 by German geologist and mineralogist Friedrich Mohs, it is one of several definitions of hardness in materials science, some of which are more quantitative. The method of comparing hardness by seeing which minerals can visibly scratch others is, however, of great antiquity, having been mentioned by Theophrastus in his treatise
The Rocks Crumble more art/garage punk ("Breathtaker") and an attempt at a slower electric track ("Lonesome Company"). The Rocks Crumble The Rocks Crumble is the eighth Jandek album, released as Corwood 0746. It is his third release of 1983, and is the first Jandek album to feature extensive use of drums and electric guitar. It was reissued on CD in 2001. "The Rocks Crumble" marks the beginning of what is often referenced as Corwood's "first electric period," since the majority of the album is played on electric guitar with clattering, earsplitting drums behind it. That said, Jandek eases us into this new phase