Certification and origin
Gold purity
- Every finished piece is tested with an X-ray fluorescence (XRF) analyser before entering stock. Pieces below their stated purity are not sold.
- Purity is shown in parts per thousand (999.9, 750, 585, 416) or karats (24K, 18K, 14K, 10K), as set out in Circular 22/2013/TT-BKHCN on measurement in gold trading and the quality of jewellery and art gold.
- Actual purity is never below the stated value. Pieces combining parts of different purities are labelled by the lower one.
Weight
- Trading scales hold a valid verification certificate and are self-checked weekly with records kept.
- Gold weight at sale is never below the stated weight. Tags show metal weight and stone weight separately.
Diamonds and gemstones
| Type | Documents |
|---|---|
| Natural diamonds from 0.30 ct | Report from an independent laboratory; report number laser-inscribed on the girdle when present |
| Melee diamonds under 0.30 ct | Specification on the warranty card: count, total carat, colour and clarity ranges |
| Coloured centre stones (aquamarine, sapphire) | Gemstone report from an independent laboratory |
Laboratory-grown diamonds
Laboratory-grown diamonds share the structure of natural diamonds but differ in origin and value. KBMC:
- States "laboratory-grown diamond" on the tag, invoice, warranty card and product page.
- Displays, prices and buys them back under a separate policy, never mixed with natural diamonds.
- Screens incoming stones with detection equipment before setting.
Traceability
Every piece has a unique identifier, laser-engraved on the piece and printed on the tag and warranty card. It links to the production order, source gold lot, test results, stone reports and every service visit. When you bring a piece back for service or buy-back, KBMC retrieves the original record from the code rather than starting from scratch.
If you doubt a result
You may ask for the piece to be sent to an independent laboratory. Process and timelines are on Complaints. If the result shows lower purity or weight than stated, KBMC refunds the testing fee and compensates the difference.