Found an expired bottle of analgesic gel in my cupboard today. Around the lid there were hundreds of tiny, as best as I can describe, glass needles.
The seal on the jar was broken some time ago, I’d say it has been sitting untouched in my cupboard for probably 3 years.
Glass needles? Perhaps just crystallized gel that seeped from under the cap or was already residue when the cap was last closed.
Some of the ingredients likely evaporated, leaving behind others that were dissolved but now have formed solid crystals. Here’e an example:
Looks almost exactly like that!