I've listed a brief description of the magical qualities of each magical type below. I did some more research into the Spells since released for Heroquest and the expansion packs and was surprised to see so many. I went back and re-examined my lists to change and modify spells so that they retained originality and abandoned some others that too closely resembled existing spells. I thought about drawing a new elemental to match the HQ cards but decided to go with something a little different, but I did keep the scroll effect and the elemental focus.
Let me know what you think.
Ice Magic engages the element of Ice to control weather and summon forth caustic coldness and fashion it into shapes and forces inc. ice-based beasts. Ice magic allows the caster to resist heat.
Auric (or Gilded) Magic taps into the deep reservoir of intuitive knowing of the operation of world forces deep inside the earth and deep inside the mind. It involves Detection Spells and power of Metals. The Auric Sorcerer relies on stores of gold to enact many spells inc. the ability to turn a creature to gold, superheat gold to act as an explosive grenade or weapon enhancement or tear through walls with molten torrents.
Weedcraft engages the ability to tap into the physics of plantlife and exercise control over greenery to manipulate the harmful and helpful aspects of plants. Weedcraft involves rapid growth of tangling, toxic weeds, toxins and poisons, bountiful food sources and healing herbs, as well as the growth and command of giant ferocious plants.
Ember Magic engages intense destructive fire spells from sources of fire such as torches, fireplaces or firegems. It also taps into the red wavelength of light allowing infra red vision, allows the caster to resist cold, and use fire for explosive, guiding or protective purposes.
Tempest Magic engages the elements of Strong Wind and Destructive Invisible Forces. Using a wide range of powerful currents to teleport, create confusing fog, travel safely over traps, blast through doors, levitate creatures or objects or summon a ferocious elemental.
Chthonic Magic engages the Undead both Evoking and Dispelling. This powerful darker set of arts allows a magician to weild a powerful two-handed sword by calling on their primal ancestor, stitch together corpses to create an abomination, restore lifefore or cause the dead to expel their treasures from the grave, divine secrets, plant suggestions, harm from great distances, and summon a powerful skeletal gaunt.
Waftcraft engages the subtle elements of Breeze, Draughts, Smoke, Air currents and Stealth. The magician has the power to clear the clouds above to read the stars and gain benefits for the whole party, to turn themselves or a group invisible and remain so even when acting on the environment, to exploit cracks to gain access to sealed sections of map, convince creatures through whispers to abandon their weapons and other subtle arts that employ gentle wind.
Tectonic Magic engages the elements of Hardened Earth, Raising/Lowering Land & Quakes to manipulate ground and stone to devastating effect, cause or cure petrification and cast on themselves or others a range of strong protections.
Aegis Magic solidifies Auric currents to create immensely powerful protective shields and wards from plants, animals, evil, spirits/ghosts and elements as well as the ability to permanently sharpen weapons and confuse with illusion.
Psyche Magic exploits the tapped power of the mind allowing shape-changing, telekinesis and powerful tricks of the mind such as ESP and hypnosis and impenetrable energetic wards.
I'm sure there are Weedcraft adepts out there too.
The Magical Type 'Ice Magic' is not exclusively reigned to Ice but also allows manipulation of water. 
