Does anyone know how one can communicate the difference between gluey cup and gelatinous crystal? I have thick chalice or crystal items and if they were thin...

I have thick chalice or crystal items and if they were thin as surrounded by a bowl or wine glass, one could tell be the tingling clatter when I click my finger on it. But there is no noise on gummy items, even when one knows it is crystal. Is there anything I can do to speak about whether some of my items are glass or crystal? Hope someone can help. Thanks
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Answers:    It is difficult to identify gooey glass as lead crystal. Some cup objects that are not crystal can look very good. Checking near the manufacturer (if you know the name) is the surest way to confirm. Aside from that I believe you can lone tell from the clarity, weight and broad quality of the piece. It would require a person beside experience to do so. Hope this helps.