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diamond

Diamond is the birthstone of April. This gemstone is sometimes called the king of gemstones. It is said to be the hardest gemstone on earth, and its strong shine is exceptionally beautiful. Colorless is the most common, but it comes in a variety of shades including yellow, pink, blue, orange, and green.

Karatz GemMagazine
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[On sale July 20th at 10 PM] "Limited to 13 Stones" Diamond Gacha: Win a FANCY VIVID Yellow Diamond (with sorting report) worth 22,800 yen. One loose stone. (Multiple purchase discount available.)

[On sale July 20th at 10 PM] "Limited to 13 Stones" Diamond Gacha: Win a FANCY VIVID Yellow Diamond (with sorting report) worth 22,800 yen. One loose stone. (Multiple purchase discount available.) Sale price¥2,580
[On sale May 23rd at 10 PM] "Limited 9 Stones - Shinjuku Pop-Up Celebration" All stones with Central Gem Laboratory sorting (3.0-3.5mm, VS-SI clarity) "Multiple purchase discount available"

[On sale May 23rd at 10 PM] "Limited 9 Stones - Shinjuku Pop-Up Celebration" All stones with Central Gem Laboratory sorting (3.0-3.5mm, VS-SI clarity) "Multiple purchase discount available" Sale price¥3,980
[On sale August 12th at 10 PM] "Limited to 15 Stones" Diamond Gacha featuring rare butterfly-cut diamonds "Multiple Purchase Discount Available"

[On sale August 12th at 10 PM] "Limited to 15 Stones" Diamond Gacha featuring rare butterfly-cut diamonds "Multiple Purchase Discount Available" Sale price¥5,980
【8/30 22時販売】イエローダイヤモンド 4.0mm/0.270ctルース(UNDER N(VERY LIGHT YELLOW), SI-2)

【8/30 22時販売】イエローダイヤモンド 4.0mm/0.270ctルース(UNDER N(VERY LIGHT YELLOW), SI-2) Sale price¥29,800
【8/30 22時販売】ダイヤモンド 4.4mm/0.309ctルース(D, VVS-1, 3Excellent)

【8/30 22時販売】ダイヤモンド 4.4mm/0.309ctルース(D, VVS-1, 3Excellent) Sale price¥79,800
南アフリカ産ダイヤモンド原石（ソーヤブル） 0.271ct原石

【#202607 Akihabara Pop-up Store - Currently Removed】【Listed as 12563268】Rough Diamond (Sawable) from South Africa 0.271ct Sale price¥88,800
ダイヤモンド 0.380ctルース(D, VVS2, 3Excellent)

[#202607 Akihabara Pop-up Store Carry Out] [32501946 Listed] Diamond 0.380ct Loose (D, VVS2, 3Excellent) GIA Sale price¥110,000
ロシア産ダイヤモンド原石（ソーヤブル） 0.101ctルース

Russian rough diamond (sawable) 0.101ct loose Sale price¥22,800
ボツアナ産ダイヤモンド原石（ソーヤブル） 0.140ct原石

[Posted as 12563267] Rough Botswana Diamond (Sawable) 0.140ct Sale price¥44,800
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
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
南アフリカ産ダイヤモンド原石（ソーヤブル） 0.353ct原石

[Listed as 12563271] Rough Diamond (Sawable) from South Africa, 0.353 ct Sale price¥128,000
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 ダイヤモンド 0.50ct ハーフエタニティリング

【Lottery Sale ①_202608_05】K18WG Diamond 0.50ct Half Eternity Ring Sale price¥128,000
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
イエローダイヤモンド 0.245ctルース(FANCY INTENSE ORANGY YELLOW, SI1)

【#202607AkihabaraPop-upOutOfStock】【Shinjuku Marui Annex 202605 OutOfStock】【#202604KobeOutOfStock】【#202509ShinjukuMarui OutOfStock】Yellow Diamond 0.245ct Loose (FANCY INTENSE ORANGY YELLOW, SI1) Sale price¥55,800
ダイヤモンド 4.45mm/0.324ctルース(D, VVS1, 3Excellent) GIA&中宝

[Lottery Sale 1_202608_11] Diamond 4.45mm/0.324ct Loose (D, VVS1, 3Excellent) GIA & CBT Sale price¥98,000
ダイヤモンド 4.42mm/0.330ctルース(E, VS1, 3Excellent) GIA

【Lottery Sale ①_202608_10】Diamond 4.42mm/0.330ct Loose (E, VS1, 3Excellent) GIA Sale price¥98,000
インターナリーフローレスダイヤモンド（H&C） 3.9mm/0.215ctルース(E, IF, 3Excellent H&C) GIA

[Lottery Sale ①_202608_09] Internally Flawless Diamond (H&C) 3.9mm/0.215ct Loose (E, IF, 3Excellent H&C) GIA Sale price¥75,800
Loose White Diamond 0.108ct (FANCY WHITE, I-1)

Loose White Diamond 0.108ct (FANCY WHITE, I-1) Sale price¥55,800
diamond

diamond Sale price¥45,800
インターナリーフローレスダイヤモンド（H&C） 3.8mm/0.206ctルース(D, IF, 3Excellent H&C)

[Lottery Sale 0731_12] Internally Flawless Diamond (H&C) 0.206ct Loose (D, IF, 3Excellent H&C) Sale price¥89,800
Pt900 カンボジア産ラタナキリブルージルコン 2.22ct・ダイヤモンド0.38ctリング 中宝ソ

[Lottery Sale 0725_14] Pt900 Cambodian Blue Zircon (Ratanakiri Blue) 2.22ct Ring with GIA Report Sale price¥158,000
Pt900 ダイヤモンド 1.00ctct リング

【#202607 Akihabara Pop-up Store - Currently Out of Stock】【Colorful】Pt900 Diamond 1.00ct Ring Sale price¥98,000
[On sale May 23rd at 10 PM] "Limited 9 Stones - Shinjuku Pop-Up Celebration" All stones with Central Gem Laboratory sorting (3.0-3.5mm, VS-SI clarity) "Multiple purchase discount available"

[On sale May 23rd at 10 PM] "Limited 9 Stones - Shinjuku Pop-Up Celebration" All stones with Central Gem Laboratory sorting (3.0-3.5mm, VS-SI clarity) "Multiple purchase discount available" Sale price¥18,800
スライストラピッチェダイヤモンド 0.228ctルース

[#202607 Akihabara Pop-up currently out of office] [Sale starts August 19th, 10 PM JST] Slice Trapiche Diamond 0.228ct Loose Sale price¥18,800
カメレオンダイヤモンド 0.255ctルース(FANCY LIGHT GRAYISH GREENISH YELLOW（カメレオン）, SI-2)

[On Sale 8/13 at 10 PM] Chameleon Diamond 0.255ct Loose (FANCY LIGHT GRAYISH GREENISH YELLOW (Chameleon), SI-2) Sale price¥79,800
イエローダイヤモンド 0.144ctルース(FANCY VIVID YELLOW, SI-2)

[Sale on August 13th at 10 PM] Yellow Diamond 3.2mm/0.144ct Loose (FANCY VIVID YELLOW, SI-2) Sale price¥55,800
H&C（ハート&キューピッド）専用スコープ（ダイヤモンド 専用スコープ) - カラッツSTORE

[Jeweler's Tools] H&C (Heart & Cupid) Special Scope (Diamond Special Scope) Sale price¥1,580
Ice blue diamond 1.2mm or 2.0mm 1 stone (VS class equivalent, round cut) {Multiple purchase discount available}

Ice blue diamond 1.2mm or 2.0mm 1 stone (VS class equivalent, round cut) {Multiple purchase discount available} Sale priceFrom ¥4,980
Lab-Grown Diamond (Synthetic Diamond) [HPHT Method] Single Loose Stone (2.0mm, 2.2mm, 2.4mm, 2.6mm) [Multiple Purchase Discounts Available]

Lab-Grown Diamond (Synthetic Diamond) [HPHT Method] Single Loose Stone (2.0mm, 2.2mm, 2.4mm, 2.6mm) [Multiple Purchase Discounts Available] Sale priceFrom ¥1,580
H&C (Heart & Cupid) Diamond 2.0mm Loose (VS Class, DG Class, 2mm Melee Diamonds) {Multiple Purchase Discounts Available}

H&C (Heart & Cupid) Diamond 2.0mm Loose (VS Class, DG Class, 2mm Melee Diamonds) {Multiple Purchase Discounts Available} Sale price¥7,980
H&C (Hearts & Cupids) Diamond 1.2mm Loose (VS Class, DG Class, Melee Diamonds) {Multiple Purchase Discounts Available}

H&C (Hearts & Cupids) Diamond 1.2mm Loose (VS Class, DG Class, Melee Diamonds) {Multiple Purchase Discounts Available} Sale price¥3,980
グリーンダイヤモンド（トリートメント）1石（約1.3mm)

Green Diamond (Treatment) 1 stone (approx. 1.3mm)《Multiple purchase discount available》 Sale price¥3,580
H&C(ハート&キューピッド)ダイヤモンド1.2mmルース - カラッツSTORE

H&C (Hearts & Cupids) Diamond 1.5mm Loose (VS Class, DG Class, Melee Diamonds) {Multiple Purchase Discounts Available} Sale price¥4,980
1 blue fluorescent diamond (H&C, 3EX, VS-SI class equivalent, 2.0mm) {Multiple purchase discount available}

1 blue fluorescent diamond (H&C, 3EX, VS-SI class equivalent, 2.0mm) {Multiple purchase discount available} Sale price¥8,980
Diamond (Old Mine Cut) 1 Loose Stone {Multiple Purchase Discounts Available}

Diamond (Old Mine Cut) 1 Loose Stone {Multiple Purchase Discounts Available} Sale price¥4,980
《Limited to 15 stones》Lab Grown Diamond Gacha💎Includes a 1.02ct/D/VS1/3EX certified lab grown diamond, usually priced at ¥50,000 (with 1 synthetic cobalt spinel as a bonus) 《Bulk Purchase Discount Available》

《Limited to 15 stones》Lab Grown Diamond Gacha💎Includes a 1.02ct/D/VS1/3EX certified lab grown diamond, usually priced at ¥50,000 (with 1 synthetic cobalt spinel as a bonus) 《Bulk Purchase Discount Available》 Sale price¥5,980
Limited Edition of 12 Diamonds: VS Equivalent Fluorescent Diamond Gacha with Bonus Mini Slice Diamond (Multiple Purchase Discounts Available)

Limited Edition of 12 Diamonds: VS Equivalent Fluorescent Diamond Gacha with Bonus Mini Slice Diamond (Multiple Purchase Discounts Available) Sale price¥6,980
Limited to 14 stones: Lab-grown diamond (cabochon cut, approximately 2.3mm) - 1 loose stone. Discounts available for multiple purchases.

Limited to 14 stones: Lab-grown diamond (cabochon cut, approximately 2.3mm) - 1 loose stone. Discounts available for multiple purchases. Sale price¥4,980
Diamond loose sorting transition fee

Diamond loose sorting transition fee Sale price¥3,000
"Limited to 14 stones" Fluorescent diamonds in rare colors such as white, orange, and green "Bulk purchase discounts available"

"Limited to 14 stones" Fluorescent diamonds in rare colors such as white, orange, and green "Bulk purchase discounts available" Sale price¥3,980
《Limited to 5 stones》Fluorescent brown diamond single loose stone (pear shape, SI clarity equivalent, 0.2ct UP) 《Bulk purchase discount available》

《Limited to 5 stones》Fluorescent brown diamond single loose stone (pear shape, SI clarity equivalent, 0.2ct UP) 《Bulk purchase discount available》 Sale price¥4,980
《Limited to 10 Stones》Diamond Gacha💎 with Gemstone Sorting (0.136ct/E/VVS-2/EXCELLENT/NONE (Heart & Cupid)) up for grabs 《Multiple purchase discount available》

《Limited to 10 Stones》Diamond Gacha💎 with Gemstone Sorting (0.136ct/E/VVS-2/EXCELLENT/NONE (Heart & Cupid)) up for grabs 《Multiple purchase discount available》 Sale price¥3,980
13-stone diamond half eternity ring set (VS class, D-G color, H&C, 2.0mm)

13-stone diamond half eternity ring set (VS class, D-G color, H&C, 2.0mm) Sale price¥158,000

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.