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Consistency
and Directionality
Consistency
- refers to the sameness of brightness, color, pattern and density of the fire
and the density and the color of the background. Brightness is judged by the
overall impression the stone gives and the one little bright spot in a corner
is ignored. Now look at each of these characteristics and note if it is consistent
across the stone. If it is inconsistent, judgment is called for . Does the inconsistency
add to or take away from the beauty of the opal? In most cases, a little inconsistency
adds to the character of the stone and makes it more attractive. Such inconsistencies
should not be faulted. Only when inconsistency causes an opal to be less attractive
should it be faulted.
Directionality
- of fire refers to whether the fire shows as brightly from one direction as
it does from another. Almost all opals will have some directionality in the
brightness of fire. Some opals want to be rings (those that look brightest when
looking straight down on them) and others want to be pendants (those that look
brightest when held vertically and slightly behind the light). Most stones look
best from one particular orientation. A truly nondirectional opal will appear
equally bright no matter what direction you tilt it. Many stones will appear
somewhat brighter in some directions than in others. An opal that looks bright
from a direction which is not seen when it is worn is a less valuable stone.
If the change is small, the stone would be graded slightly directional. If the
change in brightness is at least one brightness level, the fire would be graded
somewhat directional. If the stone looses most of its color from some directions,
then it would be graded very directional. If it looses all of its fire in some
directions, and especially if it only shows good color from one direction, it
would be graded highly direction. The more directional the stone the less valuable
it is.
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Beautiful Australian Opals