I have always wondered about what the crystal custodian is that is mentioned in the Rihne tribunal book. Does anyone ever have thought about what the Crystal Custodian is? If no one has then any suggestions about what it is are most welcome. Just eager to hear your thoughts.
/Max
For those who, sadly, don't own/have access to the Rhine Tribunal book, what does it say about it? What's the context that we do have?
Does it seem to be an animated custodian made of crystal? A person who guards a crystal? Wha'?
Basicly the only things know is its name and that it is made by Gudrun Tigurina that is the Verditi master artificer of Durenmar. That’s it.
Hmmm... well, your mage owes my mage a rook of vis for it, I know that too.
Crystal Custodian... man, the name could lead one anywhere...
I'd say the following are true:1) Some sort of automaton
It's both artwork and functional
It appears that the "crystal" element is there even tho' it doesn't necessarily have to be - that's flash.
The Crystal aspect in fact adds something to it as well- maybe minor, maybe hidden or unexpected, but something that couldn't be achieved with a stone custodian or iron custodian, etc.
Altho' "crystal" evokes rock-crystal, it could also be of ice, or some magical ice-like substance (harder than steel, blah blah blah, yadda yadda yadda.)
Just going freeform (that is, not just canon), I'd say that "Crystals" have the following advantages re Shape/Form - aquam, ice, seeing thru rock, seeing thru solids, trapping/holding energy, invisibility, regrowth of rock/self, healing other stuff, healing the mind, purity, purifying things, fracturing/bending light/rainbows/spectrums, perhaps seeing magical things/invisibility, scrying, clarity, clairvoyance... probably some other stuff.With those elements, could go anywhere beyond/within that.
Real question is - what's it the "custodian" of???
Maybe you are overthinking it again Cuchul, likely its nothing more than an enchanted kitchen wench with the task of looking after Gudrun's prized glassware! 
Verditii get off on creating interest through over-embellished rumors of their trinkets amongst the chattel, lol.
It all comes down to the difference between the perception of what you are getting when buying a brand name item and what you are truly getting for your hard earned mythic pound.
Boxer you have a point but one must remember that Gudrun Tigurina earned her masters title with the crystal custodian. Therefore it must have impressed even non-verditi magi.
Cuchulainshound there is no mentioning of what the custodian is a custodian of. It is just a cool name.
They used to call him the Glass Janitor but they changed that in the interest of political correctness.
Yes Max, I know that it must be quite impressive. I was just having a bit of a lark as usual
Well i think to get any sort of inkling of what this could be, in paradigm at any rate, one would have to first determine what the title of custodian actually meant in medieval usage, since meanings do and have changed much in 700-800 years.
This site (useful for any Ars SG, no doubt) netserf.org/Glossary/f.cfm offers this meaning (found under Farm, Sheriff's): A custodian, on the other hand, directly accounted for all the revenues.
Then we have a further use of the term (not not necessarily mutually exclusive with the first) here castles-of-britain.com/castle38.htm to wit: Castellan: a person in charge of the castle, Custodian and again Custo: temporary custodian or governor of a castle or lordship.
It appears that unlike its modern usage (i.e. janitor or caretaker) it was much more a position of honour and responsibility entrusted often to a faithful slave or servant to guard AND manage a place or person(s) of great worth (castle, young nobles, treasury, etc.).
With this in mind I could posit that it might be a rather unique automata or just as easily an inanimate figure (more likely the former simply for the wow factor). As to its powers, as Cuchul suggests these could be myriad depending on what precisely is meant by "crystal" and what specific sort of "crystal" that might then be. Some possibilities construed from the matching of the item's title with likely chosen materials (also those presumably with the greatest wow factor for such a "master" work):
alternatively (hearing): as a personal or covenant guardian against plots against the magus or covenant. Not likely to be aimed at other magi given the accolades bestowed upon Gudrun for its creation.
Cinnabar (wealth, language, dragons?) A number of interesting possibilities here. In the first instance like unto the first example. The second bonus suggesting perhaps a capacity to interact with visitors/clients/etc. regardless of spoken tongue. The third suggests perhaps some powerful combat functions to protect a magus/covenant/castle against dragons (though not likely to be a much used option since ME isnt swarming with dragons).
Clear Glass (Invisibility, Seeing through something). Useful options but not wholly satisfactory for the wow factor compared to more precious materials, not to mention again the unlikelyhood of widespread acclaim for a magical scrying device.
Crystal (water-related effect): Certainly the most in keeping in with the device's title but in the Bavarian Forest not seemingly too useful unless it is perhaps a custodian of the forest imbued with weather enchantments.
Diamond (versus demons): Now this strikes me as possibly the most likely both for the preciousness of the material (wow factor) as well as its usefulness with regard to demon protection/combat/slaying effects, especially in light of the targets which overly proud Verditii tend to be for demons.
Emerald (calm, snakes and dragonkind) the first being again generally useful to keep covenfolk/castlefolk/villagers pacified and dutiful to the rightful masters. The second following the thinking mentioned above re "dragons". Not overly exciting perhaps even if the material is precious.
Garnet (bonds of commitment, repel insects, strengthen body and mind, vigor): a pretty stone but again not much in the way of wow-factor compared to other likely possibilities. Generally useful first option for effects akin to that mentioned for "calm" just above. Second option is again useful to keep pesky insects (especially in the forest) at bay in an age long before window screens. Third and fourth options have much more general appeal especially for spellcasters who would enjoy a personal fatigue battery of sorts (provided perhaps a breakthrough beyond the canon fatigue exchange spell).
Green Turquoise (necromancy): Coordinated colour choice for a covenant located in a desiduous forest but easy to lose the device amidst the background if it wanders, lol. That said, not (again) an effect category likely to gain widespread acclaim outside perhaps House Tremere (which I doubt the device made for, frankly).
Rock Crystal (clarity): Another possibility in keeping with the device's title and perhaps quite useful for a number of Intellego effects (e.g. detect lies, sense extension, etc). Not overly precious material not overly exciting effects however.
Ruby: (battle wounds, courage): Extremely useful to any covenant no doubt especially if the device is custodian for the covenant turb. A range of self evident effects here.
Sapphire (Perdo Vim against spirits): Again useful for many covenants, most notably those containing any summoners. Likely to be sought after by the Donatores for quieting the restless dead. (Then again perhaps not) 
Fairly singular in its focus though so again not overly likely.
Turquoise (necromancy): as above.
All in all it would seem the most likely choices for material would (IMO) be
Diamond, Ruby, Amethyst, Garnet (the latter more for range of useful effects than material value) in that order. Speaking entirely hypothetically mind you, comments?
gives fingers a well-deserved rest
BoXer, that's great: I've been working on somethign similar myself for, something. A think that suprised me is that there isn't any turquoise in Mythic Europe. It is first named in Europe in the C16th, and is unknown, effectively, before that time. There are turquoises that were mistaken for other things, but the "Turkish" stone isn't found in Europe.
This is suprisingly common, actually: there are heaps of modern gemstones Mythic Europeans did not know, or just lumped together. All of the really big rubies, historically, are spinels, for example.
Did we mention he was a master sculpter...it was one impressive wench
Made me laugh 
. Your SGness is definitely showing in that comment!
To correct one error in your post, however, Turquoise did not come from Turkey, but was so named because it was obtained by Venetian Merchants at Turkish bazaars and thusly brought to Western Europe. See en.wikipedia.org/wiki/Turquoise#_note-GT
Apparently it was known for almost a millennium longer in Siberia but did not gain fashion until the late Middle Ages. See jewelrysupplier.com/2_turquo ... istory.htm
Gudrun is a she
Not sure where you're getting your information- turquoise is found in the middle east and around Egypt, and was used and traded well before the time of Christ - and if it's anywhere near the Med, it certainly found its way to Europe proper.
Perhaps it was known but it is credited as having been introduced to Western Europe by Venetian Merchants trading in Turkey (with Turkish merchants who brought it from Persia) and did not gain popular fashion until the late Middle Ages/Rennaissance period.
Well, magi tend to disregard fashion if it is useful, and a bonus to necromancy is useful for a number of spells
Cheers,
Xavi
^^ Spoken like a true Tremere!