what are two physical properties of feldspar, calcite, pyrite
The only way to carve quartz effectively is by using a diamond carving tips. Steel is, unfortunately, softer than quartz. Quartz is a 7 on the Moh's hardness scale, and may be a little softer, depending on the purity of the quartz. Some minerals that are harder than quartz are topaz, corundum, and diamond.
Any felt-tipped pen will write on quartz...eg a 'Magic Marker', provided the surface is clean. If the surface is oily, wipe it down with a rag dipped in mineral spirits first. But this is subject to loss of info if specimen is rubbed. For a permanent label, use a diamond stylus as discussed above. Museums, which want a permanent marking w/o damaging the specimen, get around this problem by attaching a small label.
The only things really suitable to scribe it are a diamond stylus or a diamond-tipped scriber. hand or electric. Check with a glass studio.
