It may be the designers/companies initials.
The acronym LR stands for Long Range.
The element, Iridium
LR Stands for Long Rifle. It's a larger cartridge and carries significantly more powder. The alternative to LR is a .22 short.
Long Reach
You have to be a little more specific. In what context ?
GH is a jewelry manufacturer
what does 930 stand for
what vendor stamps SRB in there jewelry
Not Rated
Mexican Sterling
charat
I believe this is for the Royal Jewelry - RJM found page on Facebook.