Yep, what Frarc said... I don't think nowadays there are earrings that drop or are earned/crafted ingame that have special properties but I could be wrong. Mostly now they are just for decorative purposes. I think you can still make them out of different gems and they are coloured differently for each type but its so long since I tried tinkering anything.
Three things about earrings past :
1) You used to be able to get items and jewellry, including earrings, drop with specific magical properties - this was way before we got them with resists and skillpoints on them. I can't remember all of them, but you would get items with Bless, Spell Reflection, Teleport, Night Sight, Curse & Invisibilty for certain.
They had a limited amount of charges per item, ranging from about 3 or 4 charges to ...ummm ...the highest I have is around 90 charges. These were no longer dropped after the Age of Shadows expansion ( well, nightsight items do still drop though ) and were replaced by the kind of items we get now. You can still buy them on player vendors. I still treasure my carefully hoarded invis earrings as even with invis potions, they can be a lifesaver in tricky situations !
2) When tinkering jewellry, the number of gems used would show up on the item - ie if you used 77 citrines making earrings you would get a 77 citrines earrings displayed. Again, these now can be bought only occasionally on player vendors and are nice display items. The higher the amount of gems used the higher the price.
3) Anyone remember what a pain in the bum it used to be getting earrings on and off in 2D before we had the item slots that 3D had ?! hehe. You used to have to click and drag from your paperdoll and unless you had " the knack " it could prove very tricky. I remember deliberately committing UO suicide in desperation once to get the damn things off, and once I had to get my then bf to log in as me and take them off ! needlesss to say he did it first go and was very smug about it
