Hey Sombre have a look at this
http://greywolf.critter.net/ahq/spells/amethyst.htm
From the looks of it Amethyst actually have more in common with astral magic instead of death.
For their weapons I think they should have like. staff(obvious) and more importantly; enslave(for Altered Allegiance).
Also found this picture you could take into consideration while making the sprites.
http://images3.wikia.nocookie.net/wa...izard_npcs.jpg
from left to right: amethyst, grey, jade, and celestial wizard
Since I'm not sure how far along you've gotten with them I'd like to add my general thoughts to the wizards
Amethyst Wizards: Astral and some Death(most necromancers are actually corrupted amethyst wizards, we could use that)
Grey Wizards: Air magic. They're illusionists to the core. Maybe a little astral.
Light Wizards: Light Wizards are actually more along lines of Priests in Dom. They deal in banishing demons and destroying undead. I think they should have low amounts of water, astral, and fire.
Celestial Wizards: As one would expect. Heavy Astral users. Along with air and fire. When they attack someone. They make SURE they're dead after the first spell. Comets. Lighting bolts. that sort of thing.
Bright Wizards: Fairly obvious. Mainly Fire. But maybe a minor in earth for magma and the like.
Amber Wizards: They're less like wizards and more like tribal shamans. So some nature skill, but can also hold themselves in battle. They use spears instead of staves for such a reason.
Jade Wizards: These ones are the Druids. Big boost of Nature magic.
Gold Wizards: Earth magic users. Known to be alchemists.
If you want some ideas for spells without having to flip through the book you can use this link here:
http://greywolf.critter.net/ahq/professions/wizards.htm