Antique Imperial Gold Romanov Tsarist Brooch Royalty Ducal Crown Cipher Royal RU

  
For your consideration is an exceedingly rare and historically important original antique c. 1890 imperial old mine / rose cut diamond, sapphire, and ruby brooch with royal crown and coronet and coat of arms monogram. Coronet features 7 points, each point embellished with an old mine rose cut natural diamond. Constructed from solid hand-chased 18K yellow gold with 84 silver imperial ducal crown applique. The imperial royal cypher monogram is missing one small ruby. No apparent markings / Kokoshnik / makers marks. Measures approximately 33.0mm x 23.0mm x 3.0mm.