SPECTROLITE CLASSIFICATION

Class A+

Characteristics:
- rare colours, e.g., violet, red and gold
- unusual patterns of colours
- unusual sizes, size over 40 mm

Colour:
- one colour or multi-coloured
- intense or bright colours
- bands or zones of particular colours
- colour(s) visible as a uniform surface
- bands visible with distinct borders
- annular (ring-like) patterns visually well placed and with distinct borders

Purity:
- no mineral inclusions
- no light and/or dark streaks or bands
- no scaling visible as bright spots or scaly areas
- no coloured bands of poorly distinguishable twinning
- no hairline fractures, cracks or clefts

Cut:
- stone cut in the right direction
- colour visible evenly over the whole surface of the cut stone
- form and symmetry of the stone perfect
- quality of the cutting perfect
- polishing, vitreous lustre

General description of class A+:
The best and most exquisite quality, including unusual colours and colour patterns and also large-sized stones displaying one or more colours.

Class A

Colour:
- one colour or multi-coloured
- colours intense and bright
- colours in bands or zones
- colours visible on a uniform surface

Purity:
- no mineral inclusions
- no light or dark streaks or bands
- no scaling visible as bright spots or scaly areas
- no coloured bands of poorly distinguishable twinning
- no hairline fractures, cracks or clefts

Cut:
- stone cut in the right direction
- colour visible evenly over the whole surface of the cut stone
- form and symmetry of the stone perfect
- quality of the cutting perfect
- polish, vitreous lustre

General description of class A
The best and most exquisite quality.

Class B

Colour:
- one colour or multi-coloured
- colours intense and bright
- colours in bands or zones
- colours visible on a uniform surface

Purity:
- minor isolated mineral inclusions
- isolated, very thin light or dark veins
- some coloured bands of poorly distinguishable twinning
- very slight scaling
- no hairline fractures, cracks or clefts

Cut:
- stone cut in the right direction
- colour visible over the whole surface of the polished stone
- form and symmetry of the stone almost flawless
- quality of the cutting almost perfect
- polish, vitreous lustre

General description of class B:
Very high quality and rich in colour

CLASS C

Colour:
- one colour or multi-coloured
- colourful
- varying in darkness and lightness
- colours in bands or zones
- colours visible on an almost uniform surface

Purity:
- mineral inclusions, but insufficient to affect the richness of colour
- light or dark veins, but insufficient to affect the colour on the surface
- twin lamellae visible in coloured bands
- somewhat visible scaling, cracking or fracturing

Cut:
- cut in a less than optimal direction
- possible flaws in form and symmetry
- minor flaws in cutting and polishing

In Class C, only one of the inclusions or imperfections can exist in any particular stone.

General description of class C:
Good quality, colourful and aesthetically beautiful