Stress fissure («sun spangle») in baltic amber
Natural etching structure on a crystal face of diamond (trigons), polarised light
Twin-crystal of chrysoberyl
Bubbles and swirls in moldavite (natural glass)
Epigenetic inclusion (probanly melanterite) in quartz, Brazil, crossed polarisers
Fire opal, Mexico
Inclusions of fossil plant debris in opal from Wollo, Ethiopia
Inclusions of hematite in aquamarine, Tanzania

Terminology – Diamond Colour Table

Established according to the international rules of CIBJO (in French: Confédération Internationale de la Bijouterie, Joaillerie, Orfèvrerie des Diamants, Perles et Pierres)

Current Terminology
Former Terminology
Finest White + D River
Finest White E River
Fine White + F Top Wesselton
Fine White G Top Wesselton
White H Wesselton
Tinted White I Top Crystal
Tinted White J Crystal
Slightly Tinted K Top Cape
Slightly Tinted L Top Cape
Tinted M-Z From Cape to Yellow

The coloured diamonds, otherwise referred to as ”fancy coloured diamonds" are not listed in the above table.

Diamond Purity Table

The purity of a diamond is to be examined and judged under tenfold magnification of an achromatic, aplanatic magnifying glass in normal light by a practiced specialist.

IF Internally Flawless, Pure “Loupe clean" diamond, absolutely transparent, free of inclusions and internal features.
VVS, (VVS1), (VVS2) Very, very small inclusions, which for an expert, are very difficult to detect under 10x magnification.
VS, (VS1), (VS2) Very small inclusions, which are difficult to for an expert to detect under 10x magnification.
SI Small inclusions, easy to detect under 10x magnification, but are not visible to the naked eye.
I 1 (Piqué I) Inclusions, which are immediately detectable under 10x magnification, but which do not impair the brilliance of the stone.
I 2 (Piqué II) Larger and / or numerous inclusions, which can be clearly seen with the naked eye through the upper part of the stone and which only slightly impairs the brilliance.
I 3 (Piqué III) Large and / or numerous inclusions, which are very easy to detect with the naked eye and which significantly impairs the brilliance.