5 major gems

Brazilian copper rutilated quartz 1.647ct loose stone Sale price¥6,980

Brazilian copper rutilated quartz 1.352ct loose stone Sale price¥6,980

[Published on 12563859] Australian black opal, 1.184ct loose stone Sale price¥45,800

[Listing 12563862] Australian Black Opal 1.392ct Loose Sale price¥69,800

【9/1 10 PM Release】Colombian Emerald 0.123ct Loose Gemstone Sale price¥18,800

[9/2, 10 PM release] Madagascar Padparadscha Sapphire 0.497ct Loose Stone, DGL Certified Sale price¥69,800

[On sale 9/1 at 22:00] Pigeon Blood Ruby 0.350ct Loose Stone AIGS Sale price¥49,800

[Available 9/2, 10:00 PM] Pigeon Blood Ruby 0.325ct Loose Stone, JTL Certified Sale price¥69,800

[On sale 9/3 at 22:00] Sri Lankan Purple Sapphire 0.556ct Loose Gemstone with Identification Report Sale price¥55,800

【Available 9/3 at 10:00 PM】 Sri Lankan Purple Sapphire 0.376ct Loose Stone with Appraisal Report Sale price¥35,800

[Available 9/3, 10 PM] Sri Lankan Purple Sapphire 0.258ct Loose Gemstone with Identification Report Sale price¥25,800

【Available 9/3, 10:00 PM】 Sri Lankan Blue Sapphire 0.451ct Loose Gemstone with Appraisal Report Sale price¥29,800

Russian rough diamond (sawable) 0.101ct loose Sale price¥22,800

[Posted as 12563267] Rough Botswana Diamond (Sawable) 0.140ct Sale price¥44,800

[On sale May 29th at 10 PM] "Checker x Sui" Koshu Kiseki Cut Mexican Fire Opal (usually 79,800 yen) Gacha with only 10 stones available. Win a Fire Opal (and receive one Contraluz!). [Multiple purchase discount available] Sale price¥3,980

[Lottery Sale ②_202608_10] Yellow Sapphire 2.190ct Loose GIT Sale price¥158,000

[Featured in 12563725] Sri Lankan Pink Sapphire 0.319ct Loose Sale price¥29,800

[Published 22602679] [Calafuri] Pt900 Thai Ruby 1ct Ring Sale price¥298,000

K18YG アイドクレース/ベスビアナイト 0.908ct・ダイヤモンド0.19ctリング鑑別書

[Lottery Sale 0731_13] [Colorfury] K18YG Idocrase 0.908ct Ring with appraisal report Sale price¥128,000

[Published on 22602652] [Colorful] K18 Synthetic Opal Pendant Top Sale price¥16,800

Pt900 スターサファイア 0.744ct・ダイヤモンド0.167ctリング鑑別書

【22602701掲載】【Karafuri】Pt900 Star Sapphire 0.744ct Ring Sale price¥128,000

Pt900 マンダリンガーネット 1.15ct・ダイヤモンド0.11ctペンダントトップ（ネックレストップ）鑑別書

[22602704 Posted] [Colorful] Pt900 Mandarin Garnet 1.15ct Pendant Top Sale price¥110,000

Pt900 ロンドンブルーダイヤモンド 0.13ct・ダイヤモンド0.40ctリング鑑別書

[Published in 22602703] [Kalafull] Pt900 Ice Blue Diamond (Treated) 0.13ct Ring Sale price¥98,000

Pt900合成アレキサンドライト0.41ct・ダイヤモンド0.54ctリング鑑別書

[Lottery Sale 0812_08] Pt900 Synthetic Alexandrite and 0.54ct Diamond Ring with Certificate Sale price¥128,000

Pt900 モザンビーク産ルビー 4mm/0.3ct ・ダイヤモンド0.16ctペンダントトップ（ネックレストップ）鑑別書

[Lottery Sale 0812_05] Pt900 Mozambique Ruby 4mm/0.3ct and Diamond 0.16ct Pendant Top (Necklace Top) with Identification Report Sale price¥59,800

[On sale 8/23 at 10 PM JST] Sri Lankan Yellow Sapphire 1.100ct Loose Stone, Japan/Germany certified Sale price¥49,800

[On sale August 25th, 10 PM] Ruby 0.168ct Loose Stone Sale price¥11,800

[On sale August 25th at 10 PM] Ruby loose stone, 0.268ct Sale price¥15,800

[On sale August 27th at 10 PM] Sri Lankan green sapphire 0.354ct loose stone with certificate Sale price¥12,800

[Listed as 12563271] Rough Diamond (Sawable) from South Africa, 0.353 ct Sale price¥128,000

[Featured on 12563911] Colombian Pyrite and Mica in Emerald, 0.409ct Loose Gemstone Sale price¥32,800

[Listing #12563493] Sri Lankan Blue Sapphire 0.434ct Loose Gemstone Sale price¥22,800

[Listed as 12563918] Sri Lankan Purple Sapphire 0.730ct Loose Stone Sale price¥55,800

Pt900/K18 ルビー 0.28ct・ダイヤモンド0.20ct リング鑑別書

【#202607 Akihabara Pop-up Store - Currently Displayed Off-site】【On Sale June 22nd at 10 PM】【Colorfully】Pt900/K18 Ruby 0.28ct, Diamond 0.20ct Ring with Appraisal Sale price¥98,000

[Lottery Sale 1_202608_04] Pt900 Benitoite (USA) 0.152ct / Diamond 0.58ct Ring Sale price¥188,000

インターナリーフローレスダイヤモンド 0.300ctルース(D, IF) GIA

[Lottery Sale ①_202608_12] Internally Flawless Diamond 0.300 ct Loose (D, IF) GIA Sale price¥118,000

K18WG パライバトルマリン 0.09ct・ダイヤモンド0.06ctリング（CuO:1.0%、MnO:0.4%）ソーティング（一般社団法人宝石貴金属協会）

[22602666 listed] [Colorful] K18WG Paraiba Tourmaline 0.09ct Ring Sale price¥198,000

[Item ID: 22602669] [Karafuri] Pt900 Ruby 0.58ct Ring Sale price¥98,000

[Published 22602698] [Karafuri] K18 Ruby 6.74ct Ring Diamond 0.91ct with identification report Sale price¥228,000

American Herkimer Diamond (Rock Crystal) 5.5mm/0.534ct Loose Sale price¥8,800

American Herkimer Diamond (Rock Crystal) 5.3mm/0.594ct Loose Sale price¥7,980

【Lottery Sale ①_202608_05】K18WG Diamond 0.50ct Half Eternity Ring Sale price¥128,000

コロンビア産パイライト・雲母インエメラルド 5.5mm/0.614ctルース鑑別書

[Published on 12563914] Loose Colombian Pyrite and Mica in Emerald, 0.614 ct Sale price¥45,800

カメレオンダイヤモンド 0.212ctルース(LIGHT BROWNISH GREENISH YELLOW（カメレオン）, SI-1)

[Published on 32501973] Chameleon Diamond 0.212ct Loose (LIGHT BROWNISH GREENISH YELLOW (Chameleon), SI-1) Sale price¥64,800

オレンジダイヤモンド 0.348ctルース(FANCY VIVID YELLOW ORANGE, VS-1)

[Featured in 32501971] Orange Diamond 0.348ct Loose Stone (FANCY VIVID YELLOW ORANGE, VS-1) Sale price¥128,000

イエローダイヤモンド 0.144ctルース(FANCY VIVID YELLOW, SI-2)

Yellow Diamond 0.144ct Loose (FANCY VIVID YELLOW, SI-2) [Listed as 32501969] Sale price¥55,800

ファンシーディープイエローダイヤモンド 3.6mm/0.190ルース(FANCY DEEP ORANGY YELLOW, SI2)

【#202607AkihabaraPopUpTakeOut】90002505NewYearLuckyBag2025_【On sale Dec 14, 10 PM JST】Fancy Deep Yellow Diamond 3.6mm/0.190ct Loose (FANCY DEEP ORANGY YELLOW, SI2) Sale price¥39,800

[#202607 Akihabara Pop-up Store - Currently Displayed] [12563067 Listed] Padparadscha Sapphire 0.649ct Loose Stone Sale price¥128,000

KARATZ Custom Made

Why not take your favorite gemstone that you found at KARATZ and have it made into custom-made jewelry? It will be made by skilled Japanese craftsmen.
We carefully craft each piece of jewelry, starting with the stone setting, to match the individual characteristics of the gemstone.

KARATZ・Five Commitments

So that more people can feel closer to jewellery and enjoy it easily.
We will introduce KARATZ's thoughts on products, the attention to detail and efforts in selecting gemstones and creating jewelry.

KARATZ's Initiatives and Social Contributions

We will introduce KARATZ's efforts, including nurturing the next generation and business collaboration to develop the industry, and supporting children in Sri Lanka, the land of jewels.

KARATZ Books

These are books that KARATZ has been involved in writing, supervising, and planning. They are all books that allow you to enjoy gemstones from various angles. You can also purchase them directly.

jeweler's tools

For those who want to enjoy jewelry more but don't know what tools to use, we will introduce tools that are also used by KARATZ staff. You can also purchase them directly.