Custom Natural Diamond Jewelry & Fine Diamonds | Weiss Diamonds Tokyo

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Weiss Diamonds is Tokyo's only English-friendly wholesale-direct diamond boutique, located in Okachimachi — Japan's largest jewelry district, just minutes from Ueno. For over 30 years we've supplied GIA, IGI, and CGL-certified natural diamonds to jewelry stores across Japan. Now we sell directly to you, cutting out the retail chain entirely and passing those savings on.

Whether you're searching for a custom engagement ring, a loose fancy color diamond, or finished fine jewelry, our private showroom gives you access to inventory that never reaches department stores or brand boutiques. No pressure, no markup, no intermediary.

We regularly welcome customers from Singapore, Hong Kong, Australia, and the US who visit Tokyo specifically to shop with us — whether for a custom engagement ring, a finished diamond necklace, or a one-of-a-kind fancy color stone.

Book a consultation, we'll have pieces ready that match exactly what you're looking for before you arrive.

newly arrived diamond jewelry

新入荷ダイヤモンドジュエリー

Diamond Rings

ダイヤモンドリング

Diamond Necklaces

ダイヤモンドネックレス

diamond bracelets

ダイヤモンドブレス

diamond earrings

ダイヤモンドイヤリング

loose diamonds

ダイヤモンドルース

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jewelry

ジュエリー

diamonds

ダイヤモンドルース

reviews

お客様の声

Nancy

April 2026

★★★★★

CEO Adi is very friendly and professional. Nice experience!

Shimon B

March 2026

★★★★★

I bought my engagement ring for my wife here and absolutely loved their service! Adi, the CEO, was super helpful and so nice.

Their customer service is amazing as well. I highly recommend them if you are looking for an engagement ring or nice diamond rings at a reasonable price.

Nick R

January 2026

★★★★★

I purchased my engagement ring from Weiss Co. and had a great experience from start to finish. I chose a marquise-shaped diamond engagement ring despite having limited knowledge about diamonds, but Adi and his team took the time to clearly explain everything and made the entire process easy and reassuring.

They were also incredibly accommodating with a tight timeline, and the ring resizing was handled smoothly and professionally. Communication was clear, honest, and responsive throughout, which gave me confidence in my decision.

Thank you to Adi and the entire Weiss team for your expertise and support, I truly appreciate it.

  • Certified Diamonds

    Choose from diamonds that come with authentic third-party certification from trusted laboratories.

  • Custom Design

    Create your unique jewelry piece at an unbeatable price.

  • Lifetime Guarantee

    Enjoy a lifetime guarantee on resizing, polishing, and coating by our experienced staff.
    Get 100% trade-in value for a future upgrade.

    (The upgrade is at least double the original purchase (any discounts disqualify))
  • Established Expertise

    Over 30 years of experience serving clients worldwide, with a wide range of choices and budget-friendly diamond imports.