Help with 14K Gold Pin Rubies & Diamonds

[silvercrown]

This is a lovely, 14K (marked 585), pin set with old diamonds and rubies. It appears to have entwined initials, MM? We believe it is late Victorian. It has a very early safety catch and a tube hinge. It has an extended pin stem. Curious about your thoughts as to meaning, origin, or any other thoughts you may have about the pin. We are a bit confused about the significance of the crown at the top. After the 585 mark there is an Greek omega. Thanks!

Silvercrown

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[SimonJersey]

Good evening

I'm going to have a stab at this...
It looks to be a Russian Imperial Cipher (a monogram of MM Intertwining surmounted by a crown) - the Imperial Crown of Russia at the top. This may have been made as a gift or a royal commemorative piece - the initials MM could be for Grand Duke Michael Mikhailovich.
A date of late 19th Century seems correct to me.
The 585 might possibly be 584 in the image - which would be a Russian standard of 14K, saying that the Russian Hallmark is usually stamped as "56" (56 Zolotniks = 14K)
I may try and do further research as this looks to be an interesting piece, thank you for sharing it on the forum.

Regards
Simon
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