Lead Crystal

[Cave Keeper]

Are lead crystals man-made? Is it a form of glass? Or is it artificial quartz?

If so, how does one distinguish between a natural colorless quartz sphere and a colorless lead crystal ball?

 

[CaptAubrey]

it's a form of glass. the addition of lead a) makes it feel heavier, and b) increases the refractive index so it appears less "glassy."




it's unusual for rock crystal quartz to be 100% clean, especially in something as large as a "crystal ball." you may be able to spot tiny included minerals or "fingerprints" (healed fractures) under magnification. in contrast, lead glass should show tiny gas bubbles and "flow lines."




there are plenty of other methods (refractive index, optic character) to separate the two, but they require some laboratory equipment.