There is no standard measure.
It measured by the density of the size from the hydrometer.
Disdrometer is used to measure hail occurrence and size if that is what you mean by measure
there is a device called a hydrometer that measures humidity. theres a unit to measure heat called a calorie. those are two to measure it!
To measure, or measuring is the use of units to find a size of quantity
A Purple Gem is called a Amethyst
A loose gem.
Idaho is called the Gem State.
It is called the opal.
The measure of the size of something in three-dimensional space is its volume.
In Sanskrit 'gem' is called 'ratnam(n)[ रत्नम्]'.
There is nothing called a "gold" "gem". Something is either made of gold or it is a gem, but it is not both.
Most gem-quality diamonds found are about the size of a pea.
Gem master is a rhinestone software similar to photoshop
Protractor
The value depends on the quality, size, and cut.
Diamond is a mineral and a gem. The main ore of diamond is called kimberlite.