I assume you mean lead, not led https://en.wikipedia.org/wiki/Lead_glass#Safety
That was about all I was able to find on the subject, I would like to learn more. I was under the impression that glass was the same hardness, with quartz being harder. One might think that the addition of lead to make the glass easier to work at lower temps would result in less hardness, rather than more. Were any of our usual vendors using leaded glass?
Sorry for the mis - spelling. You are in fact correct. The Chinese do things a bit differently than us here. Their glassworkers are in a factory type environment with each blower labeled by numeric code. This is where the JJ, DS, DH, all came from - who even know's if there's a real Anne Meng? lol
There can be 20 distributor's selling the same product and not even know who touched or made (let alone what it's made of) the pieces in question.
In fact, I had worked two pieces sent to me by the same person. Both from the same vendor and both fab eggs. One was lead based and the other was fine. They both etched but the lead one would not let me dig any deeper than a half a millimeter. To give you a comparison, I like to go as deep as 3 mm at times. Hardness makes no difference as I can etch into quartz as well as other minerals. Lead based glass can only be etched using acids and creams which also means it's NOT boro. Boro can't be acid etched as it's lab grade glass. In order to be classified as lab grade it has to be able to stand up to solvents that could compromise the structural integrity if the glass.
I belong to a forum for glass blowers, sanders, and so on and so forth but as we all know I'm pretty new to the game as well. I might not know all the science yet but I can tell you guy's I've seen how their glass reacts to my abrasives. Another thing I would like to add that may offer some more insight for my FC brethren is that I flame polish my pieces after I scratch em. 3 separate times, with 3 different pieces, once I hit it with my torch I heard an immediate POP! Each one broke.
Hence Scratched Glasses new saying...
"don't flame polish the Chinese ones"
One more thing to add, in case anyone wants to know what I spray with I use 180 grit aluminum oxide.