Direct from Duende, a compiled list of the damage type of each spell:
fungal growth ACID
acid breath ACID
acid blast ACID
air blast AIR
air evocation AIR
landslide BASH
waterspout BASH
ember carom BASH
necrotic explosion BASH
tremor BASH
telekinetic bash BASH
ice wind COLD
ice whip COLD
frost COLD
frost breath COLD
icebolt COLD
chill touch COLD
ice evocation COLD
iceball COLD
conjure boulder EARTH
multiply magic ENERGY
thunderclap ENERGY
magic missile ENERGY
cause light ENERGY
telekinetic wave ENERGY+MENTAL
flintstrike FIRE
spark FIRE
reflective fireball FIRE
flame wind FIRE
firebolt FIRE
fireball FIRE
fire evocation FIRE
high explosive FIRE
fire breath FIRE
cause serious HARM
cause critical HARM
steam evocation HARM
harm HARM
abjure HOLY
divine calling HOLY
electrogenic growth LIGHTNING
lightning breath LIGHTNING
lightning bolt LIGHTNING
chain lightning LIGHTNING
shocking grasp LIGHTNING
telekinetic explosion LIGHTNING
energy orb LIGHTNING
lightning evocation LIGHTNING
call lightning LIGHTNING
telekinetic punch MENTAL
shadow light MOONLIGHT
enervation NECROMANTIC
energy drain NECROMANTIC
kill NEGATIVE
leech NEGATIVE BY DEFAULT
conjure ironbolt OTHER
summon stake OTHER
quicksilver blast OTHER
telekinetic pierce PIERCE
gas breath POISON
telekinetic slash SLASH
color spray SUNLIGHT
channel faith VARIABLE
ghoststorm VICTIM'S WIELDED DAMTYPE
water evocation WATER