250 carat Diamond- uncertain amount as can be auctioned; very few diamonds of this size25 carat Diamond- $1 million to $2 million; for a lower quality stone2.5 carat Diamond - $5,000~$8,000Another AnswerYou can buy a 2.5 carat diamond today on Blue Nile and spend from US$12,000 to US$16,000.Also, a 15 carat diamond is available on Blue Nile today for just over US1,000,000.
The value of a diamond depends on its cut, its clarity, its colour and its carat weight. A local jeweler can give you the answer you want.
A 15/100s carat diamond is on the small side for a single diamond; you may be able to purchase one for US$100 - US$500, depending on its colour and clarity.
The closest we can come to finding such a diamond for sale online is for a 14.03 carat diamond, currently priced at US$781.608. This is an F colour, round cut with clarity of SI1. This calculates to US$55,710 per carat. Can you do the math for a 15 carat diamond? If you want to purchase another gem stone, your price would be different. Also, the metal, design and setting would be an additional expense.
Cubic Zircons are often meant to mimic diamonds. Since CZs have a more dense specific gravity than diamond -- Wikipedia indicates at least 1.6 times that of diamond. This means that carat weight would be less for the CZ to equal the carat weight of a diamond, both being equal in size. Using the number 15 indicates that you're looking for a large stone. In this case, you may want to go by measurement and not by carat weight. For example, a 15 carat, round diamond measures about 16.3mm across the diameter of the girdle. Presenting the data in reverse, a 15 carat CZ will weigh 1.6 times more than a 15 carat diamond: so the equivalent size diamond in weight will be less than 15 carats. Determining the carat weight of a CZ which is 16.3mm across at the girdle can be made by a jeweler who can weigh the CZ stone and give you its equivalent carat weight.
These two measurements are not directly related. If the diamond is cut in a round, brilliant cut, the carat weight may be between .15 and .20 carats. If the diamond is of a different cut, then the carat weight will be different.
A quick search found a commercially-available 15 carat stone, for which you will pay US$1,187,000+. You'll need to look hard to find a 20 carat stone for sale without finding an auction that has one that large in its catalog for sale. Once you purchase the diamond, then you'll have to pay for the setting.
A 15 carat diamond will usually cost well over $100,000, depending on the quality. The price can even go up to $500,000 or more, with a good quality cut.
A carat is a standard unit of measure that defines the weight of a diamond. One carat is equivalent to 200 milligrams. Carat sizes are also expressed as “points”, with a one carat diamond equaling 100 points, a one-half carat diamond being 50 points, a three-quarter carat diamond being 75 points, and so on.
Shopping online today, the closest we can come to this weight in this cut is 12.14 carats. This is for a D color with a clarity rating of VS2. The price is US$985,454 or a per-carat price of US$81,174. Can you do the math for the weight of stone you want to purchase?
Since diamonds are valued according to more than the carat weight, including colour, cut and clarity, you can shop at a local jeweler who can show you stones of this category, or refer you to someone who can. Shopping today on Blue Nile, where diamonds weighing just over 15 carats are available, you can buy one and spend between US$625,000 and US$1,558,000, depending on the cut, clarity and colour of the diamond you choose.
Whatever the person selling it can get for it