Vintage brooch marked '166'

Hello,
I've inherited a lovely brooch which is marked with the number 166 on the reverse. Can anyone help me to identify the maker or tell me what this means? Any help would be greatly appreciated!
Thanks.

 

Hi, GB, and welcome! I've enlarged & cropped your photos so folks can see them better:

 

Thank you very much!

 

It looks like a Czech piece, but with a safety pin clasp it could be Russian. It's not American, but where in Europe it came from is a very good question. That style shows up commonly on Russian paper mache brooches; I don't think I've ever seen it on a metal pin before.

 

Is it possible the mark (if read upside down) says "950?" That would be a mark for silver. Perhaps gold wash over silver?

 

It looks like 991 upside-down, at least to me. I've never seen anything in that construction in gold, and the metal looks stamped. The stones are rhinestones as are their settings. The odds are low of it being anything but brass and glass.

 

What got me looking at it was that the two 9's (or 6's) seem to be printed differently. Could be wear on the mark possibly. A close-up of the mark would be helpful.

 

Thanks for all your thoughts so far. Here is a close up of the stamp...

 

766 or 99L.

 

I think it's 766 also; if turned around, the loops on what would be 9s would be out of proportion. Plus, the 'L' would have a weird curve and serif.

 

Wasn't 66 a zolotnik standard?

 

Zolotnik for silver: 62, 80, 94, 96
For gold they used the gold grade .... /1000.

 

I’m in the same boat! Similar brooch, same stamp. I’m 99% sure my mom purchased this while she was living in Europe but that doesn’t narrow things down much.

 

These clasps were in the 30s and 40s. Germany or Czechoslovakia.

 

I was told that rhinestones are from 50's or later

 

much utter BS explanations on the internet.
in German - which was then still the main language - an Alsatian goldsmith by the name of Georg Friedrich Strass invented imitation stones around 1720s. as he was living near Strassburg ( no connection !) which itself is in the Rhine Valley certain "simple minds" called them Rhinestones.
wherever German was the principle language those stones were known as Strass; especially in Bohemia where the famous Gablonzer Strass comes from.
here a shocking example of made-up "knowledge" by eejets:
https://rhinestonesu.com/blog/why-are-rhinestones-called-rhinestones/

 

I'd have said German or Czech, 30s to 50s. As fid rightly says, rhinestones are way earlier. The number will be a design reference. I've a fair few similar.

 

in gold it's 585.

 

I think they may have meant Aurora Borealis crystals, which have a special coating for an extra colourful effect. AB crystals were first created in 1956, by Swarovski.

 

Yup, AB are way later.