It has been a pleasure to get to know and work with Gerry Sumner over the past four plus years. He contacted me by phone on September 28, 2016, after the company for which he worked bought out the Canadian colored diamond company with which I had been doing business. I was immediately comfortable with Gerry’s calm manner, the lack of pressure and his interest in my goals and my knowledge of colored diamonds.


Gerry is an intelligent man who has educated me about colored diamonds and the diamond businesss. He is also a congenial person with whom to converse. I have bought multiple diamonds in the past four years and benefitted from Gerry’s service, including his precise instructions with regard to wiring money to Canada and dealing with forms required by customs. I admire his integrity and look forward to our continuing relationship.


Yours truly,


I have been doing business with Gerry for over 5 years and he has been good to deal with.


He is very knowledgeable in the industry that he is doing business.





I have done business with Gerry Sumner for well over 4 years and purchased a number of diamonds on his recommendation.


His knowledge of the market has aided me in my acquisition of numerous stones. He has sent me information on the market without my asking to keep me informed.




I made my first purchase with Gerry Sumner at Hard Carbon Inc on July 22, 2020. It has been a real pleasure working with Mr. Sumner.


He is very knowledgeable in the field of colored diamonds and has taught me a great deal about the subject. He has been instrumental in helping me set up a solid investment strategy which includes colored diamonds.


Mr. Sumner's passion on the subject of rare colored diamonds is evident and really shines through with every conversation. His expertise is second to none and I look forward to working with him for many more years to come.




The purpose of this letter is to express my appreciation for your advice and counsel in upgrading my diamond collection over the last two years.


Under your guidance we have jointly converted a portfolio worth one million dollars into an investment valued at more than three million dollars. Based on my experiences in purchasing and selling diamonds, your knowledge of the diamond industry and business acumen are outstanding and have been invaluable to me.


Thank you for your professionalism and being a mentor to me in buying and selling diamonds. I am most grateful for your friendship.




I have dealt with Mr. Gerry Sumner, through his entity, Hard Carbon for several years. In each and every such instance, Mr. Sumner has delivered the items as represented. 


I have found all of my dealings with Mr. Sumner to be satisfactory. 


Very truly yours, 


I’ve had the pleasure of dealing with Hard Carbon, Inc. for some time now.


This company is so refreshingly different from other diamond-related companies in Canada that it was a huge relief to find it. 


Elsewhere, a hard-sell modality with wildly exaggerated claims as to current values and future appreciation was the norm. To the point that, however much I had previously nurtured a fantasy that Canadian firms must necessarily be honourable and upright in ethics due to the common-sense and low-key nature of so much of that nation’s citizenry, exposure to the robber-bandit mind-set of firms dealing in diamonds and other precious gems in greater Toronto had re-cast that image of Canadians into a far less favorable image.


I’m sorry to report that I had begun to distrust them all, frankly. I feel very lucky to have discovered Hard Carbon, Inc.


With Hard Carbon, Inc., responsiveness to customer questions, thorough explanation of the subtleties of diamonds as potential investment, and communication of realistic potential expectations on appreciation and long-term value all combine to leave a customer feeling listened to and positively nurtured, rather than being taken advantage of. 


Owner Gerry Sumner has deep experience in the diamond field, has worked with other firms in the past, and has markedly improved on the customer focus that his predecessors often treated lightly.


As an advisor on my very modest diamond investment portfolio, I feel I can trust him to acquaint me with what to expect in an honorable, non-inflated way, and it is for this major reason that I recommend his firm to anyone contemplating the purchase, or eventual sale of, diamonds and other gems, both in the form of loose stone and in settings.





It is with pleasure I write a reference letter for Gerry Sumner and Hard Carbon Inc.


I made my first diamond purchase from Hard Carbon Inc. on January 24 2020. Since then, I have purchased multiple diamonds from Gerry.


The knowledge that Gerry brings in the field of coloured diamonds is quite extensive. He is very straight forward, honest and fair in his business dealings.


I would recommend Gerry without reservation based on the pleasant experiences I have had in the short time that we have done business together.




I have been doing business with Gerry Sumner, at Hard Carbon, Inc. since March 2013 and have made multiple purchases and exchanges in that time. I have found him to be honest, above board and keeps his commitments. For people who are looking for doing business in the colored diamond market I would recommend him without reservation.


If you have any specific questions, I would be happy to provide my phone number to answer them.



I have been working with Gerry Sumner since March 31, 2016 when I purchased my first diamond from him. Since that first experience, I have purchased and traded several diamonds and my portfolio has grown significantly. I have found Gerry to be excellent to work with and professional in all dealings. He has also provided what has proved to be excellent advice and timely feedback on my portfolio and the diamond market. He provides information and advice that is accurate and with proper support and context in which to make informed decisions. I look forward to continuing my relationship with him in the future.


Yours Truly, 


I have been dealing with Gerry Sumner for about 7 years and with Hard Carbon since it opened their doors.


I have referred other investors to Mr. Sumner (Hard Carbon) for colored diamond investing.


I have always found Mr. Sumner to be honest and performs transactions in a timely manner.


I have found Mr. Sumner to give an accurate picture of the colored diamond industry and also Hard Carbon to not only just sell you products but to also liquidate holdings if the market is favorable to the individual’s situation.


It's nice to see Hard Carbon going through the accreditation process and helping to bring transparency to this industry.


Yours Sincerely,


I wanted to express my thanks for finding a new home for my colored diamond jewelry that had been on the market for over two years without any interest. You were able to find an interested party within weeks after we first spoke. That was fantastic.


You were upfront with the actual value of the diamonds, by showing me comparables of other like diamonds and their values. I was hoping to be able to make the exchange without additional monies out of my pocket but once it was all over, my colored diamond portfolio went from a huge negative amount to a positive amount.


Now we are no longer investing in colored diamond jewelry but investing in loose colored diamonds again, and with highly valuable diamonds. I cannot thank you enough. I cannot wait to see how things turn out for my Purple Pink collection in a few years.


Thank you very much,


I have been a client of Gerry Sumner since April 15, 2016. I can confirm that I have made many purchases with Gerry and each time he has delivered goods as agreed on in a timely manner.


Gerry receives, returns my calls and answers all my questions in a prompt and professional manner.




I can’t tell you how much I appreciate the experience I had selling one of my diamonds through you. 


After I got burnt badly in a natural coloured diamond investment scam a few years back I had lost all trust in anybody working in this niche. I thought I’d never be able to sell any of my diamonds confidently. 


Well Gerry you certainly changed that and I am beyond grateful for that! 


It's a combination of things you provided which made me feel safe, protected and confident during the entire process. Your passion, competence and market insight around rare natural coloured diamonds is always present. Your professionalism and attention to the smallest of details is truly appreciated and you being so well connected to be able to select the right buyer from your seemingly endless list of industry connections was simply impressive.


You made it all happen Gerry. Thank you for everything!


R. L.

We have purposely hid our clients names and addresses for the letters above, however, if you would like to speak with our references directly, please feel free to contact us and we can provide contact information for clients who are ready and willing to talk with you about your decision to work with Hard Carbon Inc. 

  • Committed to Customer Service

    We’re dedicated to providing you with nothing short of top-quality service.

  • Your Colored Diamond Experts

    With extensive industry experience, we know a thing or two about diamonds.

  • Unmatched Diamond Sourcing

    We search the world to find the diamond that fits with your investment strategy.

  • Custom Tailored Purchasing Advice

    We’ll help you decide on the best fancy colored diamond to invest in.

How do diamonds get their color?

Typical diamonds are made of pure carbon. Fancy colored diamonds are formed when another element is present during formation.

Learn More

Fancy Colored Diamonds - Hard Carbon Inc.Hard Carbon Inc. Fancy Colored Diamonds for Sale in Canada and the USA

Hard Carbon Inc. offers fancy colored diamonds for jewelry and more, selling fancy colored diamonds in Canada and the USA.

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