Imagine you find a tooth which you suspect belongs to a magical wolf. If it does, you could use it as an AC to target the magic wolf. But is the tooth itself magical?
Would an Intellego Vim spell detect magic on it and, at the appropriate level, be able to tell you it is a tooth from a being of the Magical realm? (and with no MR to overcome I assume - or would it have the wolf's MR?)
And does the answer change depending on whether or not the tooth contains vis?
It all depends on what you mean by it being "magical".
Is the tooth enchanted, or does it otherwise have magical powers? If so, you can detect it with the appropriate InVi spell.
Does the tooth have a Magic Might score? Then that can be detected with an appropriate InVi spell.
Does the tooth contain vis? That too can be detected by an InVi spell.
Note that different spells are needed to detect each of these things.
As for detecting if the tooth is from a being with Magic Might, I don't think that can be done with InVi - but I could be wrong about that.
Detecting what kind of beast the tooth comes from sounds more like InAn.
brings up an interesting thought- reVi gather the essence of the beast but with range:arcane connection. In theory you could pull the vis from the wolf through its tooth (obviously you would need to penetrate magic resistance), or possibly even part of it's vis, which depending on how your saga handles recovery of actual might as opposed to might points could be even more valuable...
I can't quite make up my mind about it. Say you find a lock of faerie hair, suffused with an unnatural glow (but containing no vis) - well, that intuitively feels like it should be magical in some way, and that Intellego Vim should detect something different about it compared to ordinary human hair.
If magi find the hair and do a detect magic InVi and I say, "nope, nothing!" that feels almost like I'm misleading them -
Player: "It's glowing but it's not magical. So... has some natural substance made it glow?"
Me: "Oh... well, no. Okay, you may as well know, it's faerie hair."
Player: "Right. So, it's glowing faerie hair that is not in any way magical?"
Me: "Er.... yeah."
But if it is magical, many questions are raised about MR and what exactly can be detected.
I think you are a bit too hung up on the word "magical" without defining what exactly you mean by that.
Never mind what an InVi spell could detect, what would make a thing "magical"?
In your example, where does that unnatural glow come from? If it isn't a purely natural effect, then there should be some kind of magical/supernatural power that makes it glow, right?
If the lock of hair does not have any active spell or magic power on it, if it does not contain vis, and if it does not have a Might score, and if it does not have the Gift, then what would it mean that it is "magical"?
Do you think a lock of hair from a Hermetic Magus should be considered "magical"?
Most InVi requires a different spell to determine supernatural things from each realm. This is explicit with Piercing the Faerie Veil and the aura detection spells but it is not explicit with spells like Sight of the active magics but it maybe should be true that you need “Sight of the Active Faerie Powers” to see active effects aligned to that realm. But having a rule that in that case that spell can detect any supernatural effect seems fine to me.
It is, however, explicit in the Intellego Vim guideline box that "Different spells may be invented to
detect Faerie, Divine, or Infernal effects." In other words, sight of the active magic detects magical effects.
Faeries, demons and angels are all basically spirits that coagulate around raw matter to have a physical presence. So bits separated from them either won't be actively 'magical', or they are still intrinsically part of the creature. Those bits can have residues of power and be arcane connections, of course.
That glowing faerie hair MUST still be part of the faerie's glamour, or it wouldn't glow. It's raw matter without the glamour. Angelic/demonic bodies might be more complete - you could have demon's blood, for example, and it remains blood, because the demon was able to manifest an actual body, but it shouldn't have power separated from the demon, unless the demon has a power that works that way - like 'acidic' demon blood.
Magical critters are another story. If a magic snake with shiny scales loses a scale, the scale is still magical in nature, though probably not magical enough to have might or manifest powers - though exceptions might exist, and those exceptions often contain vis all on their own.
This is kind of my question. Intellego Vim can detect magical beings, so there is something magical in the being it is detecting - this cannot just be the vis, because detecting vis is a different spell. You suggest it is the might - so does that mean a magical being with no might is invisible to Intellego Vim? If it is the might, then that suggests InVi is detecting some internal power of the being that is not present in each part of that being?
For a being to count as "magical", it needs to have a Might score, or have some magical power, or similar.
A Might score can be detected.
Magical powers can be detected.
The Gift can be detected.
Active magic effects on a being or item can be detected.
Traces of expired magic effects can be detected.
A "magical being" with no magical powers or Might score, and with no active magical effects on it - I don't see how such a being would actually be considered magical, let alone what could be found by an InVi spell.
But, if I understand your position correctly, a dragon's eye or claw is not in any way magical, and neither is faerie hair or a faerie's decapitated head, unless those things contain vis or somehow retain a magical power? So if the magi find a decapitated head, there is no magic that can determine if that is from a magical being or a mundane being? (obviously you could use InCo or InAn, as appropriate, but if the being looked just like a mundane one, that wouldn't give you an answer).
Yes, I think this may be the approach I take. But then I'm still unsure whether that residual might translates into any MR, and whether one could only detect "some trace of magic" on the thing, or whether something like Realm or power level of the creature could be detected (which then raises questions about bypassing their MR...)
I would say no on the MR, otherwise arcane connections would be useless.
As for detectability use some variation of the rules in the Guernicus section, perhaps requiring a breakthrough first to detect residual might, with the final detection being a combination of original might and time.
Detecting if an item is magical, and detecting if an item used to be part of a magical creature, those are two different things.
A dragon's claw would not be considered magical in and of itself (unless it does have some magical power or contains vis), but surely one could use appropriate Intellego spells to find out what kind of creature the claw came from. (I don't know of an example of that, but InAn magic feels right for the case of a dragon claw.)
Just knowing what kind of creature it came from won't automatically tell you if the creature is magical or not, but in many cases it will be fairly obvious. (Once you know that the claw came from a dragon, even the slightest knowledge of the supernatural will tell you that dragons are not mundane creatures.)
Also, unless it was very long ago that the dragon lost its claw, the claw will be an Arcane Connection back to the dragon, and then you can use InVi with Arcane Connection range to find out if the original owner of the claw is magical or not. (Spoiler: Dragons usually have Magic Might. Unless they have Infernal Might instead, which some dragons have.)
My understanding is this-
a faerie's body is made of incidental matter, animated by glamour. If it is detached from the faerie, but still has the form of the faerie, then it is still imbued with glamor.
A demon is made of a substance which is, in and of itself infernal, as is an angel, except divine.
So is a magical being simply a mundane being infused with magical "extra" or is the substance of magical beings itself magical.
I would suggest that paradoxically the rules for acclimation suggest that the corpus of a magical being is comprised of mundane matter which is what will remain if the vis is extracted from the corpse (as opposed to the tether which remains if it is left in place)