Our passion lies in curating a diverse and exclusive collection of diamonds, ensuring that every stone meets the highest standards of brilliance and beauty. Whether you’re seeking a rare gem or a timeless classic, R T Diamonds is your trusted source for exceptional quality.

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You can search for the diamond you want by category

New Products

Explore the Newest Additions to Our Collection.

0.176 ct <br> Fancy Intense Pink <br> SI2

0.176 ct
Fancy Intense Pink
SI2

$ 7,186

Add to cart

0.097 ct <br> Fancy Light Purplish Pink <br> SI2

0.097 ct
Fancy Light Purplish Pink
SI2

$ 1,112

Add to cart

0.125 ct <br> Fancy Vivid Yellow Orange <br> SI2

0.125 ct
Fancy Vivid Yellow Orange
SI2

$ 815

Add to cart

0.112 ct <br> Fancy Pink (Argyle) <br> SI1

0.112 ct
Fancy Pink (Argyle)
SI1

$ 8,889

Add to cart

0.258 ct <br> Chameleon Color <br> Round Shape

0.258 ct
Chameleon Color
Round Shape

$ 652

Add to cart

0.622 ct
H Color
VS2

$ 1,186

Add to cart

0.320 ct <br> Pink Color <br> Cushion Shape

0.320 ct
Pink Color
Cushion Shape

$ 445

Add to cart

0.153 ct
Fancy Light Pink
SI2

$ 1,297

Add to cart

0.896 ct
Fancy Green Blue
VS2

0.116 ct <br> Pink Color <br> Heart Shape

0.116 ct
Pink Color
Heart Shape

$ 1,186

Add to cart

Engagement Rings

Our engagement rings are custom-made, designed uniquely, and handcrafted by top Japanese artisans, ensuring a beautiful and one-of-a-kind symbol of your love.

Engagement Rings

Our engagement rings are custom-made, designed uniquely, and handcrafted by top Japanese artisans, ensuring a beautiful and one-of-a-kind symbol of your love.

Exceptional Services
Tailored To Your Every Need

Certified
Diamonds

All of our diamonds are certified by trusted certifying laboratories

Lifetime
warranty

You'll enjoy a lifetime guarantee on any resizing, polishing or coating by our expert staff.

Custom
Design

Create a unique piece of jewelry or choose from a wide variety of designs to fulfill your preferences, including rings and necklaces.

Proven
expertise

Serving customers worldwide for many years, we offer a wide range of imported diamonds to suit all budgets.

The Spark
Runs In The Family

R T Diamonds is a third-generation family business with 15 years of proud presence in Japan. We are committed to sourcing the highest quality diamonds from around the world and bringing them directly to discerning customers in Japan.

Our passion lies in curating a diverse and exclusive collection of diamonds, ensuring that every stone meets the highest standards of brilliance and beauty. Whether you’re seeking a rare gem or a timeless classic, R T Diamonds is your trusted source for exceptional quality.

NOW

THEN

Customer’s Reviews

中村賢二

13:55 06 Aug 25

There are many precious colored diamonds, including red diamonds, that can only be found here. Not only are the colors amazing, but the rarity and clarity are also superb, making it a must-see for diamond fans.
I've been here several times with my children, and the president, Roy, and everyone else there are always so warm and welcoming, allowing me to take my time looking around. This is a wonderful store that I would like to continue using.

ともとも

07:16 29 Apr 25

I chose my favorite pink diamond as a reward for my marriage and 15 years of service🩷
Since I also have parties and award ceremonies due to my work, I ordered a size that has a presence and glamor, and is classy and not offensive to customers.
I am enchanted by the elegant shine every day. So cute, so cute, so happy ~ I can’t get enough of it 💕
I'm really glad that I was able to meet such a wonderful diamond. thank you very much.

R M

04:56 29 Apr 25

I wanted to order a colored diamond ring, and I chose the rare chameleon diamond because I was drawn to the mysterious way it changes color.
Every day I am amazed at how different the colors are, such as olive green, lemon yellow, and orange, depending on the temperature and light.
The designer designed the three diamonds in a well-balanced manner, resulting in my one and only best ring✨💍✨.
It's always shining on your right hand.

kazu iwa

07:24 01 Mar 25

It has been several years since I met Roy Travin, president of RTdiamond, and I have always purchased high-quality colored diamonds from him🎵💎This time too, I made my own earrings and necklace top using a combination of colorless diamonds and yellow diamonds. 👍The president and all the staff are friendly and easy to talk to, so if you're looking for diamonds with the quality you're looking for, please come visit us! ️

Y O

09:46 23 Feb 25

Is it okay for men to wear rings with diamonds? I was worried, but I was very satisfied with the result.
For the stone, I chose a chameleon diamond that changes color.
Depending on the temperature and light, it can look from grayish green to yellowish, making it a lot of fun.
We consulted with them many times about the design, and the finished product was exactly as we had envisioned.
It's straight towards Ikeoji.
Thank you for your kind response!

H M

04:11 28 Jan 25

I had a half eternity ring made to commemorate our 10th wedding anniversary.
I ordered with absolutely no knowledge, but they carefully explained everything from the basics, such as the diamond size to the type and rank of cut, and how to set it, and I was able to create the perfect ring.
I can't help but stare at the sparkling diamond every time it catches my eye.
After browsing jewelry shops, even an amateur can see the high quality of this product.
I'm very satisfied with my purchase. Thank you!

Kenta Takamisawa (Doze)

01:53 28 Jan 25

I had been searching for a unique colored diamond for a long time.
I eventually found RT Diamond, a store that specializes in colored diamonds.
At RT Diamond, the president, Roy, was very kind in showing me a variety of colored diamonds.
He introduced me to a fancy white, which he said is popular these days. The color was truly fascinating and beautiful.
I'm sure my girlfriend would be delighted with it.
I had a great time. I'll definitely come visit again!

相澤漠（hiro）

13:26 11 Oct 24

I knew it would be very difficult to arrange fancy color diamonds in a gradient, but I never expected you to put together such beautiful pieces.
I believe only RTDiamonds could create such a perfect collection.
I am so happy that my dream has come true. Thank you very much.

Emanuela

01:13 28 Aug 24

I decided to get married and was looking for a ring. I wanted something unique, so I found RT online.
I had never heard of colored diamonds, but the president was very kind and explained it to me.
There are some really pretty colors that catch my eye, and I'm always having trouble deciding what to buy, so I fell in love at first sight and purchased a green diamond.
I'll be discussing what kind of ring I want and will even have it machined.
Thank you for making such a great connection with us.

Dカッシー

03:29 21 Aug 24

I like colored diamonds and wanted to make a ring just for me. I looked at a lot of them on the internet, but I didn't know what to do. That's when I came across RTdiamonds' page. I wanted to see them in person, so I came to the store today. The very kind President Roy showed me many colored diamonds. He also said that he will process them, so he was able to consult with me about the details, such as the design. This time, I purchased the long-desired blue diamond. I'm planning to make a ring from now on. Thank you very much.

Sabrina Mpe

07:04 23 May 24

Such a great experience! Akhil and team helped me finding my dream diamond with always friendly and very competent support … got the shipping well delivered without any problems even to germany … just love my little straight intense blue diamond ! Very fair price and amazing customer support … will definitely be back whenever looking for another fancy diamond ! They have a huge range even in extra rare colors and shapes … thank u so much again ! My full recommendation for R.T.Diamonds to buy ur special diamond !

Yu Ku

12:50 11 Mar 21

I wanted to propose to my (now) wife but had no knowledge about jewelry or diamonds.
I went to different places, and I was very unpleased with both prices and service.
RT diamond were extremely helpful and friendly. They guided me through many details I didn't know, and gave me an amazing price compared to other places.

And most importantly, she said yes!!!🎊

reuben rosen

04:50 27 Oct 20

I have been looking for a perfect engagement ring for a long time. Never could find anywhere that would listen and really hear me and my requests for the ring. RT Diamonds is the place to go to for the special gift for your loved ones. Be it engagement ring or fashion jewelry. They really listen and tailor the perfect piece to your demands and expectations.
Thank you RT Diamonds.

לירן טרוין

15:05 26 Oct 20

I want to recommend RTD, I was looking for the perfect gift for my fiancée. At RTD they made me pink diamond earrings and an engagement ring with a yellow diamond. I received excellent service and personal treatment from the best in the market.
They worked day and night to get my fiancée the perfect piece of jewelry she imagined.
There is no doubt that all the jewelry and diamonds I would like to purchase in the future I will get to RTD

guy

13:24 21 Oct 20

I had the most amazing experience during the purchase process.
The shop has a very kind, quick and professional service.
I was looking for an engagement ring diamond for my wife.
After deliberating between a white diamond or a green diamond i went for a pink diamond in a shape of a heart which was the perfect choice.
My other half loved it and i would definitely recommend on this amazing shop

In Store Appointment

While personalized suggestions, the time spent choosing jewelry will become a wonderful memory.

Yellow diamond ring

Design your own jewelry

Find The Color
That Speaks To You

Distinctive Cuts
For Distinctive Style.

Make Your Next 
Fancy Color Jewelry

Select Your Diamond

R T DIAMONDS

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New Products

Engagement Rings

Engagement Rings