Spot the Frippet: fleuron.

 Fleuron must be some rare and deadly gas, yes?

Nope.

A fleuron can either be a design representing a flower, leaves or leaf:

❦ 

(that one is used to mark divisions in blocks of type)

(that's one from the top of a building)

Spanish grandee's crown, illustration by Einzelheiten zur Genehmigung

or a fleuron can be a twiddly bit of pastry on the top of a pie:

photo by Matman from Lublin

They're both deeply good things as far as I'm concerned. 

Enjoy!

Spot the Frippet: fleuron. This word comes from the Old French flor, flower.