Simply explained, diamond carat weight is a measurement of how much a diamond weighs. A metric "carat" is equivalent to 200 milligrams. Each carat is broken down into 100 "points." This enables extremely accurate readings to the hundredth decimal point. A jeweler may define the weight of a diamond under one carat only by its "points." The same stone may be listed as 1/4 carat if it weighs 4 points or less. If a stone has no specific name, it's considered a round brilliant-cut diamond.
The standard way to determine the weight of a diamond is with a gem scale. These instruments are very precise and can measure weights as low as 1/10 of a carat. They are sensitive enough to detect the difference between diamonds of similar quality but varying sizes. For example, two round brilliant-cut diamonds of the same color and clarity but different sizes would weigh slightly more than 1 carat because the larger stone contains more material per unit volume.
A third method used by certified gemologists is by eye estimation. In this case, the jeweler looks at all the qualities of the diamond (color, clarity, size) and makes an overall judgment on its weight. Because there is no hard and fast rule for what proportion of a carat should go to color, clarity, and other factors, these estimates tend to vary quite a bit from one expert to another.
Finally, a fourth method uses x-rays to view the inside structure of the diamond.
The weight of a gemstone is commonly used to describe its magnitude. A gem's weight is measured in metric carats, which are 1/5 of a gram. Historically, gem prices have always been reported as a per-carat price. Thus the more carats you have, the higher the price.
Today's market place also values gemstones by their size. The four most common sizes are larger than one carat, equal to one carat, smaller than one carat, and less than 0.3 carats. These sizes are based on the diameter of the stone, so all stones with the same dimension will be considered the same size.
The term "gem" originates from the Latin word geminus, meaning dual or pair. This refers to the fact that many gems are formed where two crystals grow together, sometimes including some part of a third crystal.
Gems are classified according to their chemical composition and physical properties. There are five main categories: mineral, pearl, imitation, biological, and synthetic. Within these categories are hundreds of different species of minerals. Each species has its own unique characteristics that lead scientists to believe they were created by nature through some type of process. Pearl comes in two varieties: natural and cultured. Imitation jewels are copied from real gems but are made using other materials such as glass, plastic, or metal.
While a carat is the usual unit of measurement, a diamond's millimeter size informs you its genuine physical dimension. This is crucial to consider when evaluating faceting and form because, as seen in the diamond weight chart above, various shapes seem greater in size at equal carat weights. For example, a round brilliant weighs the same as an oval brilliant despite being smaller because there are more facets on the larger stone.
The size of a diamond also matters when selecting jewelry items for placement. For example, if you want to wear a ring with a large center stone, you should choose one that does not overwhelm your hand or finger. A small diamond looks better when mounted on heavier jewelry such as gold settings or platinum chains. By contrast, if you want to wear a ring with a small stone, you should select a piece that has been designed for this type of piece of jewelry. A thin metal band will look better with a small diamond than a large one.
Diamond sizes are also important to consider when buying insurance policies for precious jewels. If you have an accident and need to file a claim, the amount of insurance available may depend on the size of your diamond. The larger the stone, the higher the premium. But don't worry about these prices when shopping because we offer a wide selection of luxury diamonds at great values.
A gemstone's weight was calculated in terms of whole carats plus fractions of a carat (1/2, 1/4, 1/8, 1/16, 1/32, or 1/64); hence, a stone may be considered to weigh 3 + 1/4 + 1/16 carats. The term "carat" comes from the Latin cara, meaning "dear." A carat is the amount of granule within one given size of gem.
The standard method for weighing gemstones is by using a precision scale. The problem with this approach is that the stone may slip out of place on the platform of the scale causing inaccurate results. Also, there are times when only the mass of the stone itself is important- as when calculating the density of the stone- and not its weight relative to other objects.
In these cases, a laboratory instrument called an electron microprobe can be used to determine the exact percentage of each element within the stone. This test must then be repeated several times on separate samples of the stone to obtain accurate results that will help describe its quality range.
Finally, stones may be weighed on a micrometer gauge- a very small measuring device used by jewelers to check the thickness of thin layers such as skin or hair.
A diamond should look to be worth its weight in gold. A 1.00 carat round diamond, for example, should be roughly 6.5mm in diameter, a 1.50ct should be approximately 7.5mm, a 2.00ct should be approximately 8.1–8.2mm, and so on. The more brilliant it is, the larger it will appear under standard lighting conditions.
There are several methods used to estimate the size of a cut gemstone. One method is to compare it to other gems with known dimensions. For example, a 1.00-carat stone would be smaller than a 0.90-carat stone but larger than a 0.80-carat one. The second method is by using an optical microscope to measure the radial distance from the center of the stone to the surface of the greatest brilliance (the "greatest radius"). This method may also be used to estimate the depth of the stone; the deeper the stone, the further away it will appear when viewed under microscope lens. Stones that are only slightly below or above this range are common and do not need to be graded differently. Finally, diamonds can be weighed to determine their density. Knowing how much mass is contained in a given volume allows us to estimate the size of the stone.
The quality of the cut is important because it affects how well a stone will reflect light.
The value of a diamond is determined by its carat weight, clarity, cut, and color. As we've seen, a diamond's value is determined by a variety of elements. A qualified GIA grader considers a diamond's carat weight, cut, clarity, and color when assigning its grade. The GIA uses a five-point scale to rate each of these criteria from excellent to poor. An "excellent" quality stone would receive a grade of "4" or higher in all categories. A "good" quality stone would receive a grade of "3" or higher in most categories. A "fair" quality stone could have some minor defects that wouldn't affect its use as a jewelry material. A stone rated "poor" or below in any category should not be used for jewelry purposes.
The price you pay for a diamond is based on its quality and its carat weight. In general, cheaper diamonds are less valuable than more expensive ones of equal quality. There are many factors that go into determining a stone's cost. These include the cut, quality, and color of the diamond; its carat weight; and its source. For example, rough stones from mines in India or Brazil may be cheaper than those from mines in Canada or Australia.
In conclusion, the value of a diamond is determined by several factors including its carat weight, clarity, cut, and color.