gemmology.dev – Argyle Diamonds

Introduction

Situated in the East Kimberley region of Western Australia, the Argyle mine was
identified in 1979 when a lamproite volcanic pipe was discovered near Lake Argyle;
commercial production began in 1983 under Rio Tinto and continued until November 2020.
^[1] During its operational life Argyle produced over
865 million carats of rough, the largest diamond mine in the world by volume.

Argyle's diagnostic significance rests on colour. The mine supplied approximately 90%
of the world's pink and violet diamonds, whose colour arises from plastic deformation
of the crystal lattice rather than trace-element impurities (virtually all Argyle
diamonds are Type Ia, nitrogen-bearing). Stones are graded on Argyle's proprietary
1–9 scale, with 1 representing the most saturated pinks.

The annual Argyle Pink Diamonds Tender (a closed auction of typically 50–80 finest
pieces) was the benchmark pricing event for fancy-colour diamonds. Since closure,
documented Argyle provenance commands a rising premium; the finite supply makes fine
Argyle pinks increasingly collectible.

The Argyle Mine

History and significance:

Discovery & Operation

Discovery: 1979 (diamond pipe identified)
Production start: 1983
Closure: November 2020
Location: East Kimberley region, Western Australia
Operator: Rio Tinto
Type: Lamproite volcanic pipe

Production Profile

Total production: Over 865 million carats (all colours)
Annual peak: Up to 40 million carats/year
Pink diamonds: ~90% of world supply
Volume: World's largest diamond mine by volume
Quality: Mostly industrial; fine gems rare

Pink Diamond Production

Argyle's signature product:

Characteristics

Colour cause: Structural deformation (not impurities) ^[1]
Range: Light pink to deep purplish-pink
Rarity: Less than 0.1% of Argyle production
Unique: No other significant pink diamond source

Grading System

Argyle developed its own colour grading:

1-9 scale: 1 being most saturated
Colour descriptors: Pink, Purplish Pink, Pink Rose, Pink Champagne
Tender stones: Finest pieces sold at exclusive annual tender

Historic Source Closed

Other Argyle Colours

Beyond pink diamonds:

Champagne/Cognac

Brown diamonds in various shades
Argyle created market for these colours
C1-C7 grading scale developed
More affordable fancy colour option

Blue Diamonds

Rare Argyle production
Type IIb (boron-coloured)
Extremely valuable
Very limited numbers

Red Diamonds

Rarest of all diamond colours
Saturated pink = red
Only a handful ever found
Museum and collector pieces

Market Impact

Closure effects on diamond market:

Supply Implications

No replacement source for pink diamonds
Existing stones become finite collectibles
Prices rising since closure
Investment demand increasing

Provenance Value

Argyle certification adds premium
Documentation of origin critical
Tender history most prestigious
Lot numbers traceable to mine records

Future Outlook

Pink diamond supply constrained indefinitely
Values expected to appreciate long-term
Synthetic pinks available but distinct market
Natural Argyle increasingly collectible

Collecting Argyle Diamonds

Considerations for collectors:

Documentation: Argyle certificate essential
Grading: Understand Argyle's unique system
Investment grade: 1-3 on Argyle scale
Tender history: Ultimate provenance
Size: Larger pinks exceptionally rare
Matching: Pairs/sets extremely valuable

Other Australian Gems

Additional notable Australian production:

Gem	Location	Notes
Zircon	Various	Various colours; heat treatment common
Emerald	New South Wales	Limited production; Emmaville area
Topaz	Various	Blue, colourless; some imperial colours
Garnet	Various	Multiple species; commercial grade
Prehnite	Western Australia	Collectors; some gem quality
Jade (nephrite)	South Australia	Some production; black jade noted

Argyle Diamonds