Secondary skills are the
determining factor in which items you can salvage. Before salvaging an
item it's good to know what materials the item will yield so you can
make sure you have the appropriate secondary skill to successfully
salvage that item.
Each item you salvage will yield a quantity of one material. This
includes drops, merchant bought and player crafted items. Regardless of
the number of materials the item is composed of, salvaging yields a
quantity of only one of those materials.
Material yields are based on item type. Here's a table with the
material yields for salvaging the different categories of items: