Featured Another stone ID brooch and age please

This little brooch (1 inch square) is a bit of a conundrum to me.
The style looks fairly modern but the pin and hinge look old. Weird domed stone.
Mary Contrary flatly refuses to test the gem so no clues there. Looks a bit like labradorite but no blue flash or that opaline glass but no bubbles and it doesn’t look uniform enough to be glass but WDIK. MC is usually very good at detecting glass but she’s not playing nicely atm. A bit scratched and about to get a bath tomorrow to remove the old glue and gunk.
Looks a bit like a star/planet theme so could it be MCM? (Trying to sound like I have any idea of what I’m talking about!). But that C clasp.....?
There is a minuscule hallmark by the open part of the C clasp but unreadable at the moment - I’ll give it a good scrub and see if I can make it better. Possibly the C is over the rest of the hallmark but surely that would be a bit odd even if a replacement?
Any ideas please? Thanks for looking

 

Looks Arts and Crafts to me. Stone maybe a moonstone? Think I can see a 9 near the clasp. I like it, very wearable. See what it looks like after it’s bath.

 

Here’s a similarly dated bracelet showing moonstones of different colours. I’m just guessing about the stone though.
https://www.loveantiques.com/items/...tyle-silver-moonstone-bracelet-c1915-LA153177

 

To me.....The C clasp looks like it was broken and re purposed from what was left. I may be way off base on that, but picture 2 looks like the bottom of the clasp is rough. I'll reserve a guess at the stone until I see it cleaned.

 

I’ve started a quick clean and the stamp is a 9 followed by what looks like a 3 and anything else is obscured under the clasp. Google leads me to 935 Austria, Germany and Switzerland or 930 to the Netherlands. It does have a slightly Germanic look to it but that’s only a guess. Good eyes to spot the 9 @Houseful !

 

Very nice! Arts and Crafts for sure, clasp and hinge all original for me, all my bets are on moonstone, just not the highest quality kind.
A good wash and removing the yellow glue will improve its look

 

A few more photos after its first bath. Still a bit of yellow to remove but the stone is a little more blue now it’s cleaner.
Also more question please-
A) Arts and Crafts seems to span a wide time line from 1860-1920 with different times in different countries. Does this brooch have characteristics to pin its age down?.
B) Is there a name for this type of slightly pyramid shaped dome cabochon?
C)When did moonstone become popular?.
Thankyou

 

Aaahh, much better after bath
This is an early one, 1910s, with this C clasp and tube hinge, and the needle showing a kind of "fish tail" near the hinge.
Those rounded pyramid cabochons are called sugarloaf, yummm!

 

Awesome. Thankyou Kyra

 

It is gorgeous K. I'm with the others, A & C period and most likely moonstone.

My money is on Germany. The others mostly used assay marks at the time. Dutch 93 something silver used to be 934, btw, not 930, but that is nit picking. Now it is 935.

If German, this beauty could be called Jugendstil. Jugendstil encompasses Art Nouveau (both linear and floral) as well as what the Brits would call Arts & Crafts.

 

Thankyou for this M. My eye must be improving if I picked up that it may be German. Your wisdom and that of the other lovely people on here so willing to share is paying off .
Ive heard of Jugendstil but don’t know anything about it so now off to google more info.

 

I'm not sure where it came from I don't care, it's a beauty!!!

 

Thankyou!
All I know for certain is that it came from a car boot sale and from someone’s auntie. I love the planet type theme and exciting to find out it is older than I thought and most of all has got the forums stamp of approval!