Grimrock

Ritual of Dancing Battlemages - tested with Sancsaron level 17 Human Mage and works.
Ritual of Distant Magicks - fails, because Sancsaron does not meet the requirements. His skills top to bottom: 44,9,32,6,17,36.
Ritual of Crushing Titans - fails on Mork level 16 Minotaur Fighter with skills 16,17,2,7,0,34 because it needs a fighter with the head hunter trait to work. But Mork is one so I don't understand what's wrong.
Ritual of Enduring Essence - tested on Mork and it works giving him +1 vit, +10 health.
Ogre Recipe from Level 3 - works on Mork giving +2 unarmed combat, +1 evasion.
Recipe from Gaia Garden Library - fails on Mork, saying it needs a Fighter with the head hunter trait.
Recipe from Grondal Silverbeard - works on Mork but I can't remember the stats change completely +armor, +athletics
Recipe Raise all Weapon skills evenly - works on Mork. (Armor recipe)
Belt Ritual of Defensive Stances - works on Mork +protection +armor +health
Mask Ritual of Unwavering Resolve - works on Sancsaron giving a spell scroll and some stats I can't remember.
Belt Ritual of Quick Blade - fails on Mork and on Y. Whitefeather my level 16 Human Rogue with skills 31,10,8,24,6,0 both times saying it needs to be used on a Fighter/Rogue with the Head Hunter trait. Both have this trait.
Armor Recipe from Graendal for the Northern Ranger - game crashes after using it on Mork with error headhunterScript:613 in function warchiefVestRituals attempt to call local 'champion' (a table value). But it works on C. Stoneskull my Ranger giving +skill points and + axes.

This is explored towards end game

I have a black gem and a white gem (and red,green,blue,amethyst but they are not so special ). Can't remember which one I got from the trapdoor puzzle in the north-east of the mines.

I explored the volcanic region one level down and killed all the fire elemental lords. There are two alcoves in this room and a button. One alcove empty and one with a note. The note refers to orange,red,black and white. I don't have an orange gem. I tried to put several things (gems, stones) in the empty alcove and pressed the button, but nothing seemed to happen. I also explored a little and the button didn't seem to open something secret.

I guess I have to somehow retrieve a second black or white gem to put in the dragons mouth on this level to either activate the gaia gateway or open the door there.

I also found a golden crypt key somewhere for which I couldn't find any use. In the mines hub only the access to the ancient dig site is still locked.

4 pieces of mine ore to re-energise the gate system. There is a note near the workers quarters - there are a couple of secret buttons hidden by mine wall planks - which will tell you the code to open the gate into the energy chamber area - this gate is the east gate off the main operations room. 4 pieces of ore - 1 just below the workers quarters (drop down a secret pit), 1 in the west section of the undead area just south of the volcanic region, 1 on the middle area of the great mine chasm - where all the shrakk torr nests are and 1 in the most south west room just below. To get the ore in the middle area of the great chasm you must work your way into the Ancient Ruins (all southern wall set with poison traps). Once you have activated the energy system near the operations room with 4 pieces of ore (they must be firing in sync together!!) then the door to The Ancient Dig Site will open ---- go from there

a special crypt in the Ancient Ruins - near where you start running into mummies - congrats on finding this!

need gems yes... but which gems? Look to the different pillars near them (you will not be able to do this yet)

yellow and orange

I think they are freezing without their cozy fires