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Diamond

Diamond

Carbon gemstone with adamantine luster

Blue Colorless Pink Yellow
Optical properties

Optical characteristics

Ref. index
2.417
Luster
Adamantine
Pleochroism
None Variable depending on transparency, orientation, and variety.
Fluorescence
Variable to inert.
Origins

Source localities

Botswana Botswana: Jwaneng / Orapa
Premium

One of the most important diamond-producing countries.

25% est. supply
Russia Russia: Ural Mountains / Siberia
Legendary ★ Top Source

Classic source for alexandrite, demantoid, diamond and nephrite.

25% est. supply
South Africa South Africa: Cullinan / Venetia
Legendary ★ Top Source

Historic and important diamond source.

17% est. supply
Canada Canada: British Columbia / NWT / Labrador
Major

Known for nephrite jade, diamonds and labradorite.

18% est. supply
Australia Australia: New South Wales / Queensland fields
Commercial

Commercial sapphire and opal source; many darker blue to blue-green sapphires.

15% est. supply
Treatments

Enhancement & treatment

Clarity Enhancement Fracture Filling, Diamond Fracture filling improves apparent clarity but is not permanent under heat, repair, or harsh… Clarity Enhancement Laser Drilling Laser drilling removes or lightens dark inclusions to improve clarity appearance. It is stable… Color Enhancement HPHT Color Treatment High pressure high temperature treatment can remove brown color or create fancy colors in… Color Enhancement Irradiation, Diamond Irradiation changes diamond color by creating color centers, often followed by annealing. Disclosure is…
Inclusions

Inclusions & features

Crystals Crystal Inclusions Under 10x loupe: solid, well-formed mineral crystals trapped inside the host gem. They may… Fractures Feathers and Fractures Under 10x loupe: irregular internal surfaces that catch light and appear bright, wing-like, or… Fractures Fingerprint Inclusions Under 10x loupe: curved or wavy lines of tiny dots forming patterns that look… Clouds Pinpoint Clouds Under 10x loupe: concentrations of extremely tiny bright dots that individually are too small… Crystals Radiation Halos Under 10x loupe or microscope: a dark brown, gray, or discolored spherical zone surrounding… Multiphase Two-Phase Inclusions Under 10x loupe: a transparent irregular cavity containing both a liquid phase and a…
Identification

Instruments used

Dichroscope Reveals pleochroism, instantly eliminates singly-refractive stones 10x Loupe Your most-used instrument, start every examination here Polariscope Determines single vs. double refraction, quick and conclusive Refractometer Measures refractive index, the backbone of gem identification Thermal Probe Confirms diamond, but always follow up with a moissanite tester UV Lamp, Long Wave and Short Wave Fluorescence exposes treatments, synthetics, and origin DiamondView UV Imaging Deep UV imaging for diamond growth structure, HPHT clues, and lab-grown screening FTIR Spectrometer Laboratory infrared fingerprinting for polymers, fillers, coatings, and some treatments Raman and Photoluminescence Spectrometer Advanced spectral testing for gem ID, diamond color centers, and treatment evidence