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Quality Management

Kuwayama ensures highly elaborate made-in-Japan quality at all its manufacturing bases including overseas factories, conducting quality inspections from various angles by applying strict quality standards on a process-by-process basis. The "Kuwayama standard", which manufactures every product always at high levels of precision and accuracy, has been receiving high evaluation from customers.

Grade Assurance System

For grade assurance, Kuwayama performs highly precise & accurate destructive inspection during the raw-material stage. Furthermore, during the productization stage, Kuwayama performs non-destructive inspection to verify grades using the most advanced analytical equipment. By conducting these multiple inspections, Kuwayama assures grades as the prerequisite for jewellery products, thereby responding to customers' trust.

Diamond Authenticity Inspection System

In order to address the risk of commingling of synthetic diamonds reported in recent years, Kuwayama trades only with trustable suppliers around the world who conduct thorough inspections, and additionally in Japan, Kuwayama rechecks diamonds using the most advanced synthetic-diamond detection machines. In this way, Kuwayama always strives to deliver reliable products with a sense of security to customers.

Screening of Synthetic Diamonds

Kuwayama uses synthetic-diamond detection machines "GLIS-3000" and "M-SCREEN" to prevent commingling of synthetic diamonds into natural diamond products.

Authenticity Check Using Diamond Testers

Even after diamonds are set on the products, Kuwayama performs authenticity checks by diamond testers to prevent commingling of fake stones.

Product Inspection System

Kuwayama Group conducts thorough quality inspection at all its manufacturing plants on every required inspection item on a process-by-process basis. In addition, at the time of shipment of products, final inspection is conducted by Quality Assurance Dept., who are independent of the manufacturing teams, in accordance with the "Kuwayama product inspection standard".