Prior to the Ebonite Gemstones, there were two old companies that produced clear plastic balls with cores.
Gem Tek was one which produced clear plastic balls with bell shaped weightblocks in them which varied in color (named Gem Star, I still have a yellow one). They also had a lite blue sparkle/glitter "soft" plastic to sell against yellow dots called the "Pro Line" (had that one too).
Teknika(sp?) was another company around the same era which also made clear plastic with cores (can't remember the shape) but they were not as clear as the balls produced by Gem Tek. These companies were around about 30 yrs ago.
Not sure how "dynamic" these cores were (if at all) but they existed.
If I ever go broke, you may see my Gem Star up on ebay...haha
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Rick Leong - Ten Pins Pro Shop
Tag Team Coaching - Co-Founder
"El" Presidente of the Legion
Edited on 12/6/2008 4:59 AM