Diamond (Synthetic - HPHT) Gemstone & Information | Gemopedia by JTV | Gemopedia™

Diamond (Synthetic - HPHT)

High pressure, high temperature synthetic diamonds (HPHT diamonds) are produced in a way similar to synthetic flux grown gems, however, during the HPHT process, as the name implies, the growth chamber is exposed to high temperature and pressure. The diamonds then crystallize in a lower temperature section of the growth chamber. Colored diamonds can be produced in this way. Synthetic gems have the same chemical, optical, and physical properties of their natural counterparts, but are a more cost-effective alternative to a natural gem.

Colors

Colorless, Near Colorless, Very Light Blue, Blue To Grayish Blue, Light Gray, Green, Light Toned Pink, Dark Red, Pink To Orangy, Brownish Pink To Purplish Pink, Yellowish Green To Green To Bluish Green, Light To Dark Brownish Orange To Yellow

  • Diamond-synthetic-hpht classification

    CommonName
    Diamond (Synthetic - HPHT)
    Species
    Diamond
    Variety
    HPHT Synthetic Diamond
    Colors
    Colorless, Near Colorless, Very Light Blue, Blue To Grayish Blue, Light Gray, Green, Light Toned Pink, Dark Red, Pink To Orangy, Brownish Pink To Purplish Pink, Yellowish Green To Green To Bluish Green, Light To Dark Brownish Orange To Yellow
    AlternateNames
    GemstoneGroups
    KeySeparations
    polish luster, OTL RI, SR nature, magnification, positive reaction to diamond tester, cross shaped, square or hour glass shaped fluorescence patterns and advanced lab testing. ADR might be in cross shaped pattern.
    ClassificationComments
    HPHT=high pressure, high temperature Type IIb blue, colorless, yellow or green stones might be magnetic due to metallic inclusions.
  • Diamond-synthetic-hpht chemistry & crystallography

    ChemicalName
    carbon
    ChemicalFormula
    C
    Synthesis
    HPHT
    CrystalSystem
    Cubic
    ChemistryClassification
    Nature
    Synthetic
    Crystallinity
    Crystalline
    ChemistryComments
  • Diamond-synthetic-hpht optical properties

    Transparency
    Transparent - Translucent
    Dispersion
    Strength: moderate fire Value: 0.044
    OpticalComments
    RefractiveIndex
    Over the Limit 2.417-2.417
    Birefringence
    OpticCharacter
    NA
    OpticSign
    NA
    PolariscopeReaction
    Singly Refractive (SR) With ADR
    Fluorescence
    SWUV: Variable
    LWUV: Variable
    CCFReaction
    Pleochroism
    None
  • Diamond-synthetic-hpht characteristic physical properties

    Hardness
    10
    CharacteristicComments
    Streak
    SpecificGravity
    3.51-3.53 Typical:3.52
    Toughness
    Good
    Inclusions
    Elongated or rounded opaque highly reflective inclusions of metallic flux that rarely might cause the stone to be slightly magnetic. There might be clouds and pinpoints of flux in Chatham blue material. There might be impurities that might show faint color zoning in cross-shaped or hourglass pattern. Darker red stones typically will show areas of color zoning with intersecting square or cross shaped yellow areas encompassed by red. Pink stones have pink and colorless zones and might show metallic inclusions with brown halos. Irradiated green stones might have even coloration.
    Luster
    Adamantine
    Stability
    Excellent
    Fracture
    Uneven
    Cleavage
    Perfect, in four directions