Posts by KalleP
A clear mineral crystal can be worked to a lens shape with enough time and effort. Quartz, sapphire and ruby are likely candidates. Ruby lenses were common on wand style barcode reader pens. Even...
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A clear mineral crystal can be worked to a lens shape with enough time and effort. Quartz, sapphire and ruby are likely candidates. Ruby lenses were common on wand style barcode reader pens. Even...