Opal Brightness (Brilliance of fire)
The brightness of an opal (also termed brilliance) considers
the brightness and clarity, the amount and density as well as the directionality
of the play-of-colour and is rated on a scale from 1 to 5:
Level 1: FAINT
|
Opal shows play-of-colour only under
sunlight. |
Level 2: DULL
|
Opal shows some dull play-of-colour
under sunlight or spotlight.
|
Level 3: BRIGHT
|
Opal shows a nice play-of-colour under
sunlight or spotlight. |
Level 4: VERY BRIGHT
|
Opal shows a nice play-of-colour under
low light and a very good under sunlight or spotlight.
|
Level 5: BRILLIANT
|
Opal shows a bright crisp mirror-like
play-of-colour under sunlight or spotlight and often seems even brighter
in subdued light.
|
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