The Brownstone Collection · Black Pearl of Queens
Natural, warm, and completely unrepeatable — everything you need to know before you buy.
The Argyle Color Scale
Developed by the Argyle Diamond Mine in Western Australia, the C1–C7 scale is the industry standard for grading champagne and cognac diamonds. C1–C4 covers the champagne spectrum. C5–C7 covers cognac.
C5 – C7
Cognac diamonds are natural fancy color diamonds that fall in the C5–C7 range of the Argyle color scale — a deep, warm amber-brown with orange undertones that resembles the color of aged cognac in direct light.
The color comes from structural deformation inside the crystal caused by intense pressure during formation deep in the earth. This graining effect changes how the diamond reflects light, producing the warm brown tones you see. Unlike nearly every other stone in fine jewelry, no two cognac diamonds are the same shade.
The exact color — how amber, how deep, how orange the undertone — is determined by the unique conditions of that individual stone’s formation. It cannot be replicated. Not even by another cognac diamond.
C1 – C4
Champagne diamonds sit in the C1–C4 range — lighter, more golden, with a yellowish warmth that catches afternoon light in a way that reads almost luminous. Think the color of the drink they’re named after: pale gold to deep honey, depending on the grade.
C3–C4 champagne diamonds have a noticeably richer, more pronounced warmth. C1–C2 are softer and more subtle — the choice for someone who wants warmth without intensity. Champagne diamonds pair with rose gold the way no other stone does — the two warm tones meet at the same frequency.
Unlike colorless diamonds, champagne stones are specifically sought out for their beautiful natural coloring. The more pronounced the color, the more distinctive the piece.
Natural vs Lab-Grown
Lab-grown diamonds can produce fancy yellow and blue tones through chemical doping during the growth process. But the deep, complex warmth of a natural cognac or champagne diamond — the way the color shifts between amber, orange, and brown depending on the light — comes from physical graining of the crystal structure under geological pressure.
This structural characteristic cannot be engineered in a reactor at the same depth of color. A lab-grown brown diamond looks different from a natural one. For cognac and champagne specifically, natural is not a preference — it is the only way to get the real thing.
How to choose your metal
The metal you set a cognac or champagne diamond in completely changes the character of the stone. Here is exactly how each of our five metals reads — and when to choose each one.
Western Australia, 1980s – 2020
The Argyle Diamond Mine in Western Australia produced the majority of the world’s brown diamonds and was the source of most natural pink diamonds ever mined. In the 1980s, the mine began marketing its brown stones to jewelers using the terms champagne, cognac, and chocolate — replacing the industrial classification of “brown” with language that made the warmth of the stones feel luxurious.
The Argyle Mine closed permanently in 2020. Natural Argyle-origin diamonds are now finite. The color names, and the C1–C7 grading scale the mine developed, remain the industry standard for champagne and cognac diamond grading worldwide.
The mine’s closure in 2020 means that truly Argyle-origin cognac and champagne diamonds are now a finite resource. Every year, fewer of them exist on the market.
Market Context · 2025–2026
In October 2025, De Beers launched Desert Diamonds — their first major new product campaign in over a decade — built around natural diamonds in warm earth tones including champagne, sand, and blush hues. The bridal extension launched across the United States in April 2026.
The campaign confirmed what the colored diamond market has known for years: warm-tone natural diamonds are not a niche. They are a category. Consumer awareness of champagne and cognac diamonds is now at an all-time high.
Decision guide
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Natural cognac & champagne diamonds set in solid 14K gold and platinum. Handcrafted in New York City. Made to order in your size and metal.
Shop All Brownstone →Questions about stones, sizing, or custom requests? Text or call us at 929-806-1502
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Woodside, Queens, NYC
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Handcrafted fine jewelry in solid 14K gold and platinum. The Brownstone Collection sets natural cognac and champagne diamonds in our 14K brown gold alloy. Made to order in our Woodside, Queens workshop.
