John_Falstaff wrote: »Gold glyph applied to purple weapon will be capped by the quality of weapon - so it will give as much stats as purple glyph would. That said, it's still a gold glyph, and if you'll upgrade the piece, it'll be 'uncapped' to the gold quality. If you'll enchant with purple glyph - it won't get upgraded and will remain purple. All dropped pieces - people mentioned earlier - are with equivalent of gold glyphs on them, so you can upgrade all the way to gold and original enchantment will be of gold quality as soon as it's not capped by item quality itself.
Jewelry is the only exception, it does not cap the glyph quality, so you can apply a gold glyph and get full value of it even on white jewelry.