Are these black jet glass earrings Trifari?

I'm stumped on the maker of these faceted black glass button clip ons. The finding is signed 'Sterling' with a crown. I know Trifari had to switch to sterling silver during World War II. Could these be Trifari with just a crown stamp?

 

That does look like a trifari crown.

 

They did use real silver during WWII when base metals were required for the war effort. Those pieces will be stamped ‘STERLING’.
However,
Trifari prided itself on marking every single piece it produced. In fact they advertised, “If it isn’t signed, it isn’t Trifari.” Below you’ll find the most common Trifari marks:

• KTF w/an enlarged T: 1925-30’s
• Trifari + PAT PEND or PAT date: Mid-1930’s-1955 (see example above)
• Crown over T in Trifari: Mid-1939 – 1955
• Crown over T followed by ©: 1955-69 (see example below in Vintage Trifari Values section)
• Trifari in italics with no crown, sometimes followed by a © or TM: 1970’s-80’s
• Non-italics Trifari followed by TM: Late 1980’s-1999 (see example below)
• No mark: 2000-Present (pieces sold on a card marked Trifari)

I can't find anywhere that Trifari ever used only a crown.

 

Yes I couldn't find any evidence of Trifari only signing with a crown either. I was thinking it could be Trifari with only the crown stamp because of the 'Sterling' stamp taking up so much space. It's a mystery

 

The Trifari crown only has 3 points. Here's a pair of Trifari sterling earrings that sold on eBay "1943 Alfred Philippe TRIFARI Vermeil Sterling Lucite Jelly Belly Clip Earrings."

 

I'd have said no right off; they don't look like Trifari earrings.