For sterling silver jewelry, tarnish resistance testing is a mandatory quality-control step, especially for export-oriented manufacturing.

One of the most widely used methods is the Potassium Sulfide (K₂S) Tarnish Test.

What Is the K₂S Tarnish Test?

Potassium sulfide simulates a sulfur-rich environment, which accelerates silver oxidation and tarnishing. The test allows manufacturers and buyers to evaluate how silver jewelry reacts under harsh conditions in a short period of time.

Why This Test Matters for Brands

• Verifies the purity and alloy stability of 925 silver
• Evaluates the effectiveness of anti-tarnish treatments or plating
• Predicts long-term appearance during storage, shipping, and consumer wear
• Reduces after-sales complaints related to discoloration

Typical Test Procedure (Industry Standard)

• Jewelry samples are exposed to a diluted potassium sulfide solution
• Exposure time is controlled (e.g. 30 minutes to several hours)
• Surface color change, oxidation level, and uniformity are evaluated
• Results are documented and archived for batch traceability

Regent Jewelry performs this test before mass production approval, not after shipment.

We are able to provide:

• Batch-level production records
• QC inspection reports
• Tarnish test records linked to specific orders