The total intensity of the properties of the item determines the what Imbuing ingredient is received when unraveling a magic item.
The intensity of properties is weighted, for example 'mage armor' property has a weight of 1.4. These weights can be found by consulting the 'magic effects table', link above.
* <= 199 Total Intensity = Magical Residue
* 200 to 449 Total Intensity = Enchanted Essence
* 450+ = Relic Fragment
- Source:
http://uo.stratics.com/php-bin/show_content.php?content=30889