About Us
Custom Diamond
Jewellery Design
At Mendel Gems International, custom design begins long before the sketch. Every piece is born from investment-grade diamonds and coloured stones sourced directly through our DTC Botswana allocation and private master-cutter relationships in Antwerp, Jaipur, and Tel Aviv. Whether you require a flawless Type IIa centre stone, an unheated Burmese ruby, or a one-of-a-kind hand-crafted fancy cut that exists nowhere else, we reserve the rarest parcels exclusively for bespoke commissions. From concept to completion, Jeffrey Mendel and our GIA graduate gemologists oversee every detail – cut, proportion, provenance, and final polish – ensuring each creation is not only beautiful, but built to preserve and grow generational wealth. Public pricing is never displayed. All custom projects are strictly confidential and available by private appointment only.
Jeffrey Mendel is a third-generation gemologist and one of the industry’s few remaining independent rough-diamond allocation holders with permanent facilities inside DTC Botswana, Gaborone.
Raised between Antwerp and New York, Jeffrey began sorting parcels on the trading floor at age twelve alongside his father and grandfather. After earning his Graduate Gemologist diploma from GIA New York, he spent over a decade sourcing directly in Bangkok, Mumbai, Yangon, and Tel Aviv before securing personal rough allocation rights with DTC Botswana in 2015 – an investment that today grants Mendel Gems priority access to sight-holder goods that never reach the open market.
Known equally for unheated Burmese rubies, Type IIa investment diamonds, and one-of-a-kind hand-crafted fancy cuts, Jeffrey maintains direct, decades-long relationships with the world’s finest master cutters who reserve their most exceptional stones exclusively for his network.
He operates with a deliberately simple rule: only acquire and place stones he would personally own, and only with buyers who value provenance, discretion, and long-term relationships above all else.
Today Jeffrey divides his time between New York, Gaborone, and Antwerp, personally overseeing every parcel that carries the Mendel Gems name.
Mendel Gems International was formally established in 2016, though its foundations were laid decades earlier on the trading floors of Antwerp, Tel Aviv, and Bangkok. What began as a second-generation family office dealing in select diamond and colored-stone parcels has evolved into one of the industry’s most discreet and trusted private placement platforms. In 2015, Jeffrey Mendel personally committed approximately US$4 million alongside DTC Botswana, securing long-term rough allocation rights and permanent facilities in Gaborone. That single strategic investment – today valued at over US$8 million – transformed a respected boutique operation into a preferred partner for sight-holders, master cutters, and institutional buyers worldwide.
Every parcel and introduction at Mendel Gems passes through a small, deliberately lean team of veteran specialists:
- GIA Graduate Gemologists with combined 85+ years of bench and trading experience
- Former DTC sight-holder staff who managed multi-hundred-carat monthly allocations
- In-house compliance officer (former RJC auditor) ensuring every stone carries unbroken Kimberley Process and System of Warranties documentation
- Direct relationships with master cutters in Antwerp, Jaipur, Tel Aviv, and Bangkok who reserve their finest hand-crafted and proprietary cuts exclusively for our network
We do not employ junior brokers or commission-based salespeople. Every client speaks directly to a principal or senior gemologist.
Our strategy is simple and non-negotiable: source only what we would personally own, document everything as if it will be audited tomorrow, and place stones only with buyers who value provenance over price. We maintain deliberately low public visibility because our clients – family offices, legacy jewelers, private equity funds, and collectors – require absolute discretion. Inventory is never listed with public prices; opportunities are shared strictly on a qualified-introduction basis.
This disciplined approach has allowed us to place some of the rarest goods in the market – unheated Burmese rubies, Type IIa D-flawless specials, old-mine Portuguese cuts, and one-of-a-kind hand-crafted fancies – while preserving relationships that most firms can only access once or twice in a lifetime.
At Mendel Gems, we do not chase volume. We protect legacy – both the stones we handle and the trust placed in us.
Legacy,
discretion,
and direct global access.
For three generations we have quietly connected verified buyers with investment-grade diamonds and rare colored stones that never appear on the open market. From DTC Botswana rough allocations to unheated Burmese rubies and one-of-a-kind hand-crafted fancies, Mendel Gems exists to deliver opportunities that others simply cannot.
To remain the most trusted private gateway between mine, cutter, and collector — preserving generational relationships while placing only the finest, fully documented stones with clients who value provenance above all else.
Source exclusively at origin, document without exception, and introduce only to qualified principals. We never list prices publicly and never compromise discretion.
Source exclusively at origin, document without exception, and introduce only to qualified principals. We never list prices publicly and never compromise discretion.
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Strictly confidential access to off-market diamonds and colored stones.
Four Decades of Proven Access
Direct Botswana allocation • GIA veterans • 100 % documented • zero public pricing.