The Rev. Enrico Trevisi (59) a priest of Cremona was ordained a bishop on March 25 and will be installed as the 59th Bishop of Trieste on April 23. His coat of arms is:
I love the simplicity and boldness of the whole achievement. However, impalement is an odd choice considering the dexter impalement is not the diocesan coat of arms. Also, can you have Argent (silver) swords–keeping in mind grey is not a heraldic tincture or metal–on a field Argent?
No, no you can’t.
(The arms were designed and emblazoned by Renato Poletti and Gianluigi Di Lorenzo.)
EXARANDORUM 
In case of USA-tradition the choice of ‘per pale’ is perhaps odd, because all dioceses except Venice have per pale diocese/personal charges. Italy follows the Latin-european tradition in which we nearly never see the diocesan c.o.a. appear (Italy, France, Spain, Portugal. I love this design except the grey of the swords.
You misunderstand me. I know that in Europe it is not customary to impAle personal arms with diocesan arms. However, that being a general custom it still looks like that’s what is happening which is misleading. My point is this: impaling, as a general rule, is a form of marshaling two separate arms on one shield. If that’s not what’s happening then using impalement is a poor design choice heraldically speaking because it appears to be two arms marshaled together even though it may not be.
It’s rather late for a comment, but I happened to find this only today, so here goes: Marshalling of arms is an art. An art that is governed by rules and customs that are decidedly regional. What is customary, or even “de rigueur” in one region, is unknown or even unheard-of in another.
Fr. Selvester is right in that the dexter half does not show the arms of Triest. If you ask me, it refers to Our Lady “Maris Stella”. Or, if Msgr. Trevisi is a “Lokalpatriot”, this design might represent the Shrine of Monte Grisa (near Triest): https://en.wikipedia.org/wiki/Temple_of_Monte_Grisa
Most Italian bishops use arms. A lot of Italian dioceses, however, do not.
Don’t know whether these dioceses used to have any coat of arms of their own (or whether they simply employed the arms of the city), but if they have, they don’t use them now, and often haven’t used them for some (considerable) time. And as the family physician said to the middle-aged male patient: Use it or lose it. In canon law, I think, the term to use would be “desuetudo”, the opposite of custom (consuetudo).
Regards,
H.