Pink Diamond

Related: Diamond Varieties

Blue DiamondBrown DiamondDiamondYellow Diamond

Key Differentiators

• Single refractive index 2.417 — highest of any natural gemstone
• Hardness 10 — scratches all other gems
• Color from plastic deformation (graining planes), not chemical impurities
• Argyle mine (closed 2020) produced 90%+ of world supply
• Thermal conductivity — diamond tester registers positive

Natural vs. Synthetic

Synthetic pink diamond is commercially available (HPHT (High Pressure High Temperature) — De Beers, Sumitomo, New Diamond Technology, CVD (Chemical Vapor Deposition) — IIIA Diamonds, Lightbox (post-growth irradiation for pink color)). Distinguishing natural from synthetic typically requires microscopic examination of internal features.

• DiamondView (UV Fluorescence Imaging): Natural pink diamonds show broad blue fluorescence patterns; Type IIa naturals may show irregular patterned or orange-red fluorescence. Graining-related strain is visible. Synthetic: HPHT synthetic shows cuboctahedral growth sector pattern (blue and orange sectors meeting at right angles). CVD synthetic shows layered columnar growth sectors and characteristic orange fluorescence in {100} sectors.
• Spectroscopy (FTIR / UV-Vis): N3 center at 415nm (Type Ia); B-aggregate nitrogen absorption; hydrogen-related absorption at 3107cm-1 in some Type IIa naturals; NV center at 575nm/637nm may be present. Synthetic: HPHT synthetic typically Type IIa (no N3 at 415nm, no B-aggregates); CVD shows characteristic Si-V peak at 737nm; nitrogen is absent or isolated (Type Ib) rather than aggregated.
• Loupe / Microscopy — graining: Irregular wavy graining lines (pink graining) parallel to crystal faces visible under magnification. Graining planes cause the pink color via plastic deformation. Synthetic: HPHT synthetics show metallic flux inclusions (Fe, Ni, Co), rounded crystal inclusions, or are very clean with no graining planes. CVD may show columnar growth patterns or graphite inclusions.

Common Simulants

• Pink Sapphire: DR (birefringent, uniaxial negative); RI 1.762–1.778 vs diamond 2.417; hardness 9; strong pleochroism pink/pale pink; will not pass diamond thermal tester.
• Pink Tourmaline (Rubellite): DR with strong birefringence; RI 1.624–1.644; SG 3.06; strong pleochroism; hardness 7–7.5; adamantine luster absent; fails diamond thermal tester.
• Pink Spinel: SR but RI 1.718 (vs 2.417 for diamond); SG 3.60; lower dispersion; hardness 8; fails diamond thermal tester.
• Morganite (Pink Beryl): DR; RI 1.583–1.590; SG 2.72; hardness 7.5–8; much lower dispersion; fails diamond thermal tester.
• Pink Cubic Zirconia: SR; RI ~2.15 (lower than diamond); SG 5.60–5.90 (much heavier); fails diamond thermal tester; lower hardness 8–8.5.

Treatments

• HPHT Treatment (color enhancement)
• Irradiation (+ annealing)
• Surface Coating

Price Context

Price context is approximate. GemID is not an appraisal tool. Results are indicators, not certified valuations.

About Pink Diamond

Pink color in diamonds arises from plastic deformation of the crystal lattice creating slip planes (graining), not from trace elements. The Argyle mine in Western Australia (closed 2020) was the dominant source; Australian material used a grading scale of P1–P9, PP, and PC for pink and purple-pink diamonds.