Diamonds are graded according to their cut, clarity, carat weight and colour.
You can read more about each, below.
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The initials TW stand for total weight. One characteristic of every diamond is its carat weight. When a jeweler mounts several diamonds into jewelery, the jeweler may describe the total carat weight of all the diamonds as TW. A single diamond will always be more valuable based on its carat weight than multiple diamonds of the same total carat weight.
The term HS 1 is not commonly used in grading diamonds. It may be used in a different context that grade, however, but this other use is not easily found in a quick search.
In different countries you learn it at different grades. Your question needs to specify which country - or even region - your question is about.
Black diamonds are more porous and from younger sedimentary rocks, so they are not as expensive as other diamonds.
There are several colour measurements for diamonds, including grades of 'white' and grades of coloured stones. You can read more about grades of 'white' diamonds, below. You can also read more about grades of coloured stones, below.
925 Jewlery is silver and jewlers do not put diamonds on silver. Diamonds need to be set with gold or platinum. There are various karat classifications of gold (10k, 12k, etc) the different grades of gold determine the quality and "softness" of the gold.
Carbon. Coal has a few different types and grades, but hard anthracite coal is almost pure carbon. Same as graphite, soot and diamonds.
The exact number is infinite, but a finite number exists in terms of colour grades. For 'white' or 'colourless' diamonds, the grades begin with the letter D -- colourless -- and trail off to the letter Z -- light colour, with five broad categories of grades. For coloured diamonds, please review the Color Grading system, also linked below, to identify the hue, tone and saturation variables available for grading coloured diamonds. Can you do the math?
There are quite a few different grades for Cut of the diamonds, the most common cuts used are: 'Very good' 'Good' 'Fair' The cut of the diamond determines how accurately the diamond is cut according to brilliance.
You are probably referencing industrial diamonds, of which are are many, many different types, sizes and descriptions. You can read about the basic categories, below.
Diamonds are not found in a great many different places. Diamonds are not found floating in the ocean for example.
amethysts are purple in color and diamonds are more clear
Sometimes. Diamonds can come in a variety of different colour. Pink diamonds are actually among the world's rarest and most expensive diamonds.
There are many different colors for diamonds. They do in fact come in black, though they are rare. If you stumble across one, they have an almost priceless value.
No. Diamond and topaz are to different things. Diamonds are composed of carbon.
Many Grades