Re: Re: Unknown Mineral
Is the glass in hardness testing kits different than glass from ordinary windows? I have various specimens of feldspars that can easily scratch the broken window pieces I've been using to test.
Also, a jagged piece of feldspar can scratch glass more easily than a smoothly rounded quartz pebble, despite the hardness difference.
From Adelaide - September 15, 2011 at 05:43:16