No sorcery professional circle spell is purely elemental or purely spiritual. If there were such a spell, a wizard or cleric could learn it and cast it at full strength. Nor is any spell just a combined elemental and spiritual effect slapped together like layers of a sandwich. Otherwise you'd see rogues and warriors learning Blood Burst. Sorcery is unique in the way it combines and weaves together the two spheres into something entirely new. It's not like a double major in Engineering and Journalism.
Sure, we're "all purple", but there are infinite tints and shades and hues of purple. Just as there are a variety of combinations of redness, blueness, lightness and darkness in those colors, there will also often be a lore or other skill(s) that will dominate a spell's power. Thus you'll be tempted to think "this is a necro spell" or "714 isn't really elemental or spiritual", which is fine for the purposes of training strategy, but for a perspective on the concept of capital-S Sorcery, don't forget all the other mumbo jumbo I just said.
I owe you folks a long post on my devious plans for the 700s, but I haven't had enough focus to sit down and type up a good one. I know there's been a lot of anguish over the prospect of a sorecery lore review. The bottom line is that I want to do it after the elemental lores are done. More words on that (and other things) to come.
-Strath