An Altar of Enchanting is what is used to enchant a non-magical weapon or item using a soul gem. There are several located in the Chironasium in the Arcane University. Another is located in Frostcrag Spire, an add-on home located east of Cloud Ruler Temple.
- See Enchanting for more information on enchanting weapons and items.
Activate the altar and an enchanting menu will appear. Select the weapon or item you wish to enchant and the soul gem you wish to use to enchant it with. A list of applicable effects will appear (you can only add effects that you know about, i.e. you can cast a spell with that effect). Choose the enchantments you wish to add to the weapon or item and in the top box give this new item a name then simply click "create". Note, however, that cost of the enchantment and the amount of charge placed on the weapon varies depending on the strength of the enchantment you're placing on the item.
Note: If you want to make a "Cloak of Invisibility", you must use the Chameleon spell 100%. That's about as close as you can get, because if you try to use an invisibility spell, it will not show up in the spell roster.