Thanks for reaching out Joseph, I am so glad you found us!
The Crown hallmark in British hallmarking we can see in this wedding band, is the Gold Standard mark used by the Assay Offices , Birmingham, Sheffield, or London, for 18ct and 22ct gold. This means 75% of the ring is solid gold, mixed with 25% other metals (like copper, silver, or zinc) for strength and color.
The initials "JM" identifies the ring's creator, or Jewelry manufacturer rather than it being produced for a globally famous luxury brand.
