Maria & Jack Private Jewels
Not merely brilliance —
an asset that outlasts time.
"At Maria & Jack Private Jewels, we fuse your most intimate stories with the world's rarest gemstones.
This is not merely an aesthetic acquisition — it is a dual legacy of wealth and culture."
12+
Years of Expertise
34
Gemstone Origins
100%
One-of-a-Kind Pieces
GIA
Certified & Verified
Featured
This Season's Rare Selections
Burma · Ruby
Pigeon Blood Ruby
Ceylon · Sapphire
Royal Blue Sapphire
Colombia · Emerald
Vivid Colombian Emerald
Design Philosophy & Aesthetic Practice
Philosophy & Aesthetic Practice
Jack's jewellery is not mere replication. It distils the philosophical essence of America's greatest design masters,
fused with cross-cultural depth and a rare dual mastery of art and finance.
Core Design Directions
01
Emotional Narrative Bespoke Couture
情感叙事型高端私人定制
Jack's core design direction. He weaves each client's life story and personal memories into the very architecture of a piece, transforming rare gemstones into warmth-laden tokens of devotion. He is attuned to the emotional needs of high-net-worth clients — love, kinship, dynastic legacy — and designs bespoke symbols calibrated to life's defining moments.
02
East–West Aesthetic Fusion Craftsmanship
东西美学融合的精工设计
Rooted in Singapore's Asian sensibility and shaped by American modernism, Jack unites Eastern gem mastery — precision colour stone cutting, jade carving — with the sculptural confidence of Western design language. The result: pieces that preserve Eastern refinement while speaking with Western structural clarity.
03
Investment Design: Art & Asset Value
艺术收藏与资产兼具的投资型设计
Drawing on a dual background in fine arts and finance, Jack rigorously selects rare stones — Myanmar colour gems, old-mine jadeite — creating works that satisfy both the connoisseur's eye and the family office's balance sheet. Design and asset allocation, unified in a single commission.
04
Vintage Jewelry Recreation & Innovation
古董珠宝复刻与创新设计
Drawing inspiration from the canon of antique jewellery, Jack honours historical craft codes while breathing contemporary vision into each revival. Recreation is an act of reverence; innovation is the living form of inheritance — a delicate balance between what endures and what evolves.
Masters of Inspiration
The Masters Behind the Vision
Harry Winston
The King of Diamonds
Rare Stone Curation · Asset Legacy
Shared philosophy: like Winston, Jack places rare stone curation above all else, building a proprietary framework for evaluating gemstone value that no algorithm can replicate.
Both recognise the asset dimension of fine jewellery, integrating design with investment counsel for the world's foremost families and institutions.
Elsa Peretti
Queen of Organic Aesthetics
Emotional Expression · Organic Minimalism
Spiritual resonance: inspired by Peretti, Jack refuses to accumulate luxury for its own sake. Emotion is the core; the jewel becomes an extension of the wearer's identity.
A commitment to fluidity of line and wearability — never allowing design to overshadow the stone's natural beauty.
Oscar Heyman
The Jeweler's Jeweler
Extreme Craftsmanship · Rigorous QC
Craft lineage: Jack carries Heyman's legacy of extreme precision into Asian colour gemstone finishing, establishing rigorous contractual standards and provenance storage protocols.
Technical excellence as the foundation for long-term trust with high-net-worth clients across generations.
Jean Schlumberger
Master of Fantastical Naturalism
Artistic Expression · Multi-cultural Fusion
Aesthetic kinship: trained in fine arts, Jack shares Schlumberger's conviction that artistic expression transcends stylistic boundaries — never confined to a single vocabulary.
French elegance, American luxury and Eastern depth resonate across cultures within every Jack Sinclair commission.
Create Your Legend
Create Your Legend
Let your jewellery carry your story — and become a transferable work of art that outlasts time.
Collections
Investment-Grade Gemstone Series
Discover →
Pigeon Blood Ruby · Eternal Vow
Unheated · Burma, Mogok Valley
Discover →
Royal Blue Sapphire · Morning Star
Unheated · Ceylon, Sri Lanka
Discover →
Colombian Emerald · Jardin Vivant
Minor Oil · Muzo Mine, Colombia
Discover →
Ural Alexandrite · Dual Nature
No Treatment · Ural Mountains, Russia
Discover →
Paraíba Tourmaline · Neon Light
Copper-bearing · Paraíba State, Brazil
Every piece is accompanied by full provenance documentation, GIA international grading reports, and independent third-party appraisal support.
Bespoke
The Six-Step Atelier Process
From first encounter to the delivery of a heirloom — an average journey of 90 to 180 days.
Private Consultation
An intimate conversation at the Bel Air Atelier. We explore your story, aesthetic sensibility, and financial parameters — in complete confidence.
Gemstone Sourcing
Jack personally curates three to five candidate stones sourced directly from the world's finest mining regions, each with grading certificates for your review.
Artisan Sketch
Jack hand-draws a one-of-a-kind design that weaves together your narrative and the character of the chosen stone — two concepts presented for your selection.
3D Rendering
The sketch is translated into a precise digital model with photorealistic renderings. Fine-tuning is welcome before production commences.
Master Craftsmanship
Collaborating with Europe's foremost artisan workshops, every stage is documented with imagery — traditional craft meets precision engineering.
Heirloom Delivery
The piece arrives with its complete dossier: original hand sketch, GIA certificate, a bespoke Legacy Story Book, and a lifetime care agreement.
Investment Reference
Starting Investment
$50K+
Entry Collector Tier
$150K+
Investment-Grade Legacy
Bespoke
Private Arrangement
The Founder
Jack Alexander Sinclair
Founder · GIA Graduate Gemologist · Maria & Jack Private Jewels
Jack's name is a tribute to the spirit of romance, perseverance, and sacrifice. He believes that every name holds a story worth remembering.
In 2017, after losing his beloved, Jack realised that beyond memories, what truly endures are tangible assets imbued with emotion and value. In her honour, he founded Maria & Jack Private Jewels — a sanctuary where exquisite craftsmanship meets heartfelt devotion.
Today, Jack navigates the world's premier gemstone mines and elite artistic circles, uniting natural wonders and human sentiment in their most exquisite and lasting form. Every creation from Maria & Jack Private Jewels embodies a connection between geological marvels and human emotion, designed to be treasured for generations.
Discipline & Lifestyle
"Discipline is the foundation of both aesthetic clarity and rational judgment. The man who masters his own breath is the man who remains calm before a great stone."
— Jack A. Sinclair
Concierge
Begin Your Bespoke Chapter
In absolute respect for our clients' privacy, the Atelier accepts private appointments with a minimum of 72 hours' notice.
Each client is assigned a dedicated advisor. All information is encrypted and never shared.
Bel Air, Los Angeles
California, USA
By Appointment Only
72 Hours Advance Notice
End-to-End Encryption
Strict NDA Protection