1. Manufacturer's Mark:
* It could be the initials of the manufacturer or a specific workshop that crafted the necklace.
* Many jewelers have their own unique markings for identification.
2. Assay Mark:
* Some countries have mandatory hallmarking systems where jewelers are required to mark their gold jewelry with a government-approved assay mark.
* This mark could indicate the purity of the gold (e.g., 18K, 14K).
* "NS" is not a typical assay mark for gold purity.
3. Uncommon or Regional Mark:
* The mark could represent a local or regional hallmarking system that uses "NS" for a specific purpose.
4. Personal Mark:
* It could be a personal mark added by the owner, perhaps initials of a past owner.
To determine the meaning of the "NS" mark, you would need to:
* Examine the mark closely: Look for additional symbols or numbers around the "NS" that might provide more context.
* Research the history of the necklace: If you have information about the origin or age of the necklace, it could help you identify the mark.
* Consult a jeweler or expert: A qualified jeweler or goldsmith might be able to identify the mark based on their knowledge of hallmarking systems and jewelry history.
A picture of the mark and any other information you have about the necklace would help me give a more accurate answer.