The JJT probably indicates the manufacturer. The 925 probably indicates Sterling Silver. The CZ probably means that any stones set in the necklace are Cubic Zirconia.
Seta 925 is the name of a company and the metals that made the necklace and ring. A marking of 925 is at least 92.5% sterling silver.
The "925" probably refers to the purity: 925/1000 gold.
AU is the symbol for gold... 925 refers to the purity of that particular piece...
The silver is 92.5% pure, that's pretty good, and originally came from Nevada.
It may be the maker of the necklace. Like the trademark. Hope this helps.
The .925 means that the necklace is sterling silver. Silver is not usually used in its pure form, because it is too malleable and would bend too easily.
The letters "SU" could represent someone's initials or a personal monogram. The circle design around the letters might simply be decorative, or it could symbolize eternity, unity, or protection, depending on the wearer's personal beliefs or intentions.
92.5% sterling silver 7.5% copper or other metal
It means that it is gold electroplated silver. The 925 means purest silver. The piece is not gold, it is silver.
The 925 on the back of a bracelet indicates it is silver metal alloy.
The 925 is a sterling silver mark. I would doubt if diamonds were set in this . They are most apt to be crystals or paste
Star Gold "could" be the brand! 925 used mostly on silver items!