Usually this marking is used on PLATINUM a lot. It is used when jewelry is 90% PLAT and 10% IRID. IRID is the abbreviation for IRIDIUM (a silver looking alloy).
A 525 stamp indicates that the metal in the stamped piece is 52.5 percent gold. This is the same thing as the marking 14K for 14 karat gold.
As the Common Metal Marks Stamped Inside Rings, TI=Titanium
Is it real gold
Most likely the ring is stamped with 925 instead of 525. This means that the ring is 92.5 percent silver.
Sterling stamped on any item is .925 silver and .075 other base metal.
Marks stamped on a ring may tell you the manufacturer as well as the composition and metal quality.
82.5% gold /silver what ever the metal is
That number indicates the fineness or purity of the metal content. 900 means the coin is 90% of that metal.
It is the purity of that metal. which means if you melt your metal you get 72.5% pure of that metal. Just like 916 for gold and 925 for silver.
IR10k stamped on a ring typically means that the ring is made of a metal called iridium and is 10 karat gold. It indicates the composition of the metal used in the ring.
MTL could mean 'Metal' however, I also have a ring with MTL stamped on it but I am unsure of what it really does mean. I would advise you to get it checked out at a jewellers and see what it means
what does LXG stamped on gold mean