extinction angle

Once you have 10 measured extinction angles, select the one with the largest value.

Now rotate the stage counter-clockwise and measure the extinction angle.

The number of degrees the stage was rotated is the extinction angle, between 0-89 degrees.

Minerals that have no cleavage or elongation can not have an extinction angle.

Extinction angles - minerals that exhibit interference colours go dark when the microscope stage is rotated.

The extinction angle γ is related to the turn-off time t of the thyristors.

The extinction angle is the measure between the cleavage direction or habit of a mineral and the extinction.

The extinction angle is an optical characteristic and varies with the albite fraction (%Ab).

This also allows a smaller extinction angle to be used with a converter/inverter, reducing the need for reactive power support.

The resulting, slightly roughened surface alters the extinction angle of various parts of the crystal lattice, leading to this type of extinction.

In this method, the extinction angle of albite twins are measured and the largest extinction angle is used to determine the composition.

Minerals with two cleavages can have two extinction angles, with symmetrical extinction occurring when minerals have multiple angles that are the same.

For each of approximately 10 correctly oriented grains within a single thin section, measure the extinction angle of each set of albite twin lamellae and take the average.

Firstly, allowance must be made for the overlap angle μ, and secondly for an additional extinction angle γ which is needed for the valves to recover their ability to withstand positive voltage after conducting current.

The reactive power absorbed is at least 0.5 MVAr/MW under ideal conditions and can be higher than this when the converter is operating at higher than usual firing or extinction angle, or reduced DC voltage.

The composition of a plagioclase feldspar is typically denoted by its overall fraction of anorthite (%An) or albite (%Ab), and readily determined by measuring the plagioclase crystal's refractive index in crushed grain mounts, or its extinction angle in thin section under a polarizing microscope.

To facilitate measurement of extinction angles various kinds of eyepieces have been devised, some having a stereoscopic calcite plate, others with two or four plates of quartz cemented together; these are often found to give more exact results than are obtained by observing merely the position in which the mineral section is most completely dark between crossed nicols.