Join Date: May 2011
Location: Amarillo Texas
Basically glass is warm to the touch and crystalline materials are cold. Use your lips to see the difference. Glass warm, quartz cold. Any piece of glass can be used a comparison.
Quartz is doubly refractive: if you look through the stone at a spot on the other side the spot looks doubled. Glass does not do this.
Scratch tests are never recommended for precious objects: as mentioned above, glass can scratch glass, quartz will scratch quartz.
Any curious and helpful gemologist can check it and tell you with very little effort, and they should do it at no charge.
I was s professional gemologist for 39 years 😉