I think (as does Frazzle) that all Gorrors chests follow this pattern. If you find otherwise, feel free to let me know.

Chest Layout
 
Treasure #1 Treasure #2 Treasure #3 Treasure #4 Treasure #5 Treasure #6 Treasure #7
100% 100% 25% 50% 50% 100% 100%
sword of fire
axe of many runes
maiden head
vulcan hammer
raven's bill
cat'o nine tail
horn of prometheus
silent lyre
resurrect
cask ill repute
lt. heal
mod. heal
hv. heal
mod. stamina
hv. stamina
cure lt. cond
cure poison
cure paralyze
cure stone
cure disease
superman
cherry bomb
fire bomb
poison bomb
acid bomb
stink bomb
holy water
invisible potion
magic screen
magic missle
terror
dispel undead
slow
knock knock
hold monsters
whipping rocks
missle protect
armorplate
enchanted blade
haste
fireball
blink
illusion
conjure
levitate
zap undead
resurrect
armormelt
crush
confusion
wizard eye
remove curse
restfull
healfull
blades
locate object
locate person
book of shielding
book of airs
book of resting
book of barriers
book of knocks
book of direction
book of detection
book of haste
book of watchbells
book of blessings
book of charming
book of levitation
book of firewalls
book of seeing
book of unhexing
book of banishing
book of anti-magic
book of icewalls
skeleton powder
talc of tamaris
powder of creation
faerie dust
sneeze powder
flash powder
snake dust
bone dust
crushed widows
estoc de olivia
the avenger
muramasa blade
excaliber
blades of aesir
diamond eyes
maenad's lance
zatoichi bo
faust halberd
platemail+3 (U)
platemail+3 (L)
chamail doublet +2
chamail pants +2
faerie cap
mitre de sanct
cloak of fortune
staff of doom
robes of enchant (U)
robes of enchant (L)
black gown of death (U)
black gown of death (L)
armet
mantis gloves
mantis boots
forest cape
ebony plate (U)
ebony plate (L)
hi-kane-do (U)
hi-kane-do (L)
rock crystals
brimstone nugget
aromatic salts
manta roots
lion's claws
ju-ju stones
dragon's teeth
displacer cloak
crusader helm
ebony heaume
ring of truth
ring of resounding
ring of shielding
mystic's ring
ring pro frost
ring pro magic
bat necklace
amulet of spiders
amulet of stillness
amulet of airs
amulet of illusions
amulet of life
ankh of might
ankh of youth
ankh of speed
ankh of dexterity
ankh of sanctity
ankh of life
ankh of death
ankh of healing
cross of turning
cross of protection
book of demons
mana stone
stone pro airs
stone of new life
staff of charming
staff of blessing
stave of silence
staff pro paralysis
haunting stick
stave pro undead
winterwand
pandora's wand
crystal wand
wand of winds
bag of death
bag of tricks
sparkle stix
icicle stix
cracker stix
fire stix
rocket stix
amulet of asphixiate
amulet pro magic
amulet of rainbows
rod of sprites
ring of truth
ring of resounding
ring of shielding
mystic's ring
ring pro frost
ring pro magic
bat necklace
amulet of spiders
amulet of stillness
amulet of airs
amulet of illusions
amulet of life
ankh of might
ankh of youth
ankh of speed
ankh of dexterity
ankh of sanctity
ankh of life
ankh of death
ankh of healing
cross of turning
cross of protection
book of demons
mana stone
stone pro airs
stone of new life
staff of charming
staff of blessing
stave of silence
staff pro paralysis
haunting stick
stave pro undead
winterwand
pandora's wand
crystal wand
wand of winds
bag of death
bag of tricks
sparkle stix
icicle stix
cracker stix
fire stix
rocket stix
amulet of asphixiate
amulet pro magic
amulet of rainbows
rod of sprites