Glass pendants are a beautiful item of costume jewellery, but like everything they require a little care to remain looking as good as new.
Keep glass pendants in a jewellery box or other covered container - this helps them stay dust free.
Regularly wipe with a jewellery cloth.
In the case of getting grime (or food) on your glass pendant, use a soft cloth dampened with warm soapy water (not dripping wet)
and carefully wipe only the pendant.
If grime/dust makes your pendant look a little dull, carefully spray a very small amount of glass cleaner onto the corner of a soft cloth and gently wipe the pendant. Buff with the dry part of the cloth.