(urth) Violet = Plutonium?

[David Stockhoff]

I've searched Moonmilk on this with no result. Has there been any 
discussion of why Sand twice calls Violet "Plutonium"?

Note that Violet is suspected to be a (native Vironese) Trivigaunti spy. 
Also, Sand has at this point been killed and resurrected. So it's hard 
to guess whether he is malfunctioning or has been enlightened in some 
way---whether he correctly or incorrectly sees Violet as a chem---or 
something else. (Or maybe he has acquired a chem sense of humor. 
Plutonium fluoride forms violet crystals.)

What bothers me is that Siyuf herself later appears as a chem double. Up 
to that point, the reader has no particular idea that chems can actually 
fake being human, to the point that the Ayuntamiento decides to send the 
fake Siyuf home in her place---and apparently succeeds though their plan 
fails.

It's one thing if Orchid hired a chem to pleasure chem guests the way a 
brothel might hire boys and girls for different tastes (although 
apparently she did not hire boys). But how could Siyuf have not been 
able to tell, and if she could, would she have been "into it"? Where did 
these crypto-chems come from, and what do they mean? Are there others? 
Do they need brain scans of humans to give them the self-identity to act 
as doubles?

Chems, or at least soldiers, are unknown in Trivigaunti. So perhaps 
Siyuf just doesn't know what to look for, or she enjoys the novelty. Is 
Wolfe just covering his butt, showing us that the chem Siyuf would have 
been able to pass the Minister of War's, er, personal Turing test (she 
being her lover)?

Or does he simply insist that the soul is more important than the body, 
always? Am I suffering from robot racism to even raise these questions? :D