You're probably dealing with Psilochalcis, but that means the metallic purple highlights in the photo are an artifact and not true to the specimen. None of the Chacididae have metallic highlights. And 8 mm is large for the genus.

I am told that Boucek indicated that there are at least 10 undescribed species if Psilochalcis in the US and Canada. In his key, metallic conditions were referenced in a couplet that goes to the two genera Psilochalcis and Schwarzella. My contact says this is definitely not the latter. It can only be confirmed as Psilochalcis from one or more additional photos showing the venation or by having the specimen examined by a chalcidologist.

The antennal scape is totally wrong for Schwarzella. Jeff Halstead looked at Psilochalcis with the idea of doing something, and then threw up his hands in despair. LOL Maybe someone will come along and straighten it out. They are abundant in the environment, and one of the most commonly collected chalcids.