The main identification features of synthetic diamonds

  In the past, the cost of synthetic diamonds and processing is still very high, and branded jewellery in particular is still very demanding in terms of equipment, technology and techniques, but there are now a small number of synthetic diamonds in the world Put on the market, but no price advantage. However, with the development of technology, the human diamond now has a trade value.

Main identifying features.

Inclusions

  These inclusions are round, bar, plate and needle shaped and are arranged in a manner that correlates with the boundaries of the internal growth zone. The inclusions may also be particulate in shape. They are dispersed throughout the crystal. These inclusions are opaque and appear golden yellow or basaltic in reflected light, with a metallic lustre. Seed crystals and seed crystal phantom zones; seed crystal phantom zones are the areas within the diamond

  A tetragonal, single cone-shaped growth zone formed by relatively bright lines along the outward growth of a tetragonal seed crystal, which is always present whether or not the seed crystal is ground off during processing. The phantom zone is always present, whether or not the seed wafer has been worn off during processing, and is more clearly visible in the dark field or when the diamond is placed in an immersion bath.

Colour

  Most synthetic diamonds are yellow, thirsty yellow (mostly) with hourglass-like bands, while natural diamonds are colourless, light yellow and other colours. Absorption spectral lines. Synthetic diamonds lack the characteristic 415nm spectral line of the colourless-light yellow series of natural diamonds. In addition, most natural diamonds are Type Ia, while synthetic diamonds are mainly Type Ib.

In a few cases, diatomic aggregates of nitrogen are present.

Anomalous birefringence

  Under orthogonal polarisation, natural diamonds exhibit complex anomalous birefringence due to the complexity of the growth and transport processes, such as irregular bands, waves, patches and lattices, while synthetic diamonds show less anomalous birefringence. The anomalous birefringence of synthetic diamonds is less pronounced, with some synthetic diamonds showing bright bands of crosses.

Luminous characteristics

  UV fluorescence: some synthetic diamonds are inert in long-wave UV light and show moderate to strong yellow-green fluorescence in short-wave UV light, with banding, unlike the fluorescence characteristics of natural diamonds.

  The fluorescence characteristics are different from those of natural diamonds. Cathodoluminescence (under electron excitation): Synthetic diamonds: colour: yellow - yellow-green, regular zoning (main square, octahedral zones differ) Natural diamonds: blue. predominantly, lamellar growth or complex growth forms.

Crystallographic and surface characteristics

  Synthetic diamonds are often dominated by octahedral and cubic aggregates, and may develop rhombic dodecahedral, tetrahedral trioctahedral or triangular trioctahedral crystalline surfaces. The surface may show dendritic growth

The surface may show dendritic growth patterns or irregular mounds or verrucae unlike natural diamonds.