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Old 03-30-2005, 05:43 PM
Rollin Karg Rollin Karg is offline
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Originally posted by Robert Mickelsen
For instance, there is an opal green that is notorious for crackling when incased.
Robert, if that green is a fluorine opal this may help.
Years ago when we first started making colors a guy told me that the fluorine opals are made of billions of little fluorine inclusions.When you reheat you start to lose these little inclusions to the atmosphere and the more you heat the more you lose. Also the hotter the flame the more inclusions you lose and when you lose these little guys you change the LEC. The same thing happens in the pot when we make them. The longer they stay in the pot the more the LEC changes and most likely the viscosity changes too.
I remember how we were struggling to make the colors work at the time and that bit of news was just one more thing to torture us.
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