Your ability to determine an item's worth and your knowledge of magic allow you to determine the exact properties of a magic item without the use of the identify spell or similar magic.
If you know that an item is magical, you can use the Appraise skill to identify the item's properties. This use of the Appraise skill requires 8 hours of uninterrupted work and consumes 25 gp worth of special materials. The DC of the Appraise check is 10 + the caster level of the item.