Our standard size for a round sapphire is 6 mm, which is approximately one carat.
Since sapphires are usually heavier, a one carat sapphire will look smaller than a one carat diamond. It is more accurate to measure the size of the sapphire in terms of its millimeter diameter. A rule of thumb is that a one carat sapphire generally measures 6 mm.
The price of a cut sapphire can be as low as $50 per carat to over $10,000 per carat, depending on the color and clarity. Diamonds start around $3,000 per carat and top out over $25,000 per carat, depending on the color, cut, carat, and clarity.
The standard size of a one-carat gemstone is 6.5 mm in diameter. How do you determine carat weight? The starting point for measuring the correct carat weight for a gemstone is to weigh it and take note of its weight in grams. Then, divide the number of grams by 0.2 to get the carat weight.
Blue sapphires can range in size anywhere from a few points to hundreds of carats, and large blue sapphires are more readily available than large rubies. However, most commercial-quality blue sapphires weigh less than 5.00 carats.
Finger Size
The size of the finger is directly proportional to the size of the sapphire. In case she has small hands, you might not need a larger sapphire. For example, if she is UK J½ / US 5, an approx. 1.10 carat (6.20 MM) sapphire would look not too big and definitely not small.
A one carat round brilliant diamond has a width of 6.5 mm. This is reasonably big, though not as big as the oval, pear, or marquise cuts of similar weight. A one carat oval cut diamond measures around 7.55 by 5.54mm. As for marquise cuts, one carat comes to roughly 10mm x 4.75mm.
The average carat weight of an engagement ring in the United States is 0.9 Carat. Choosing a 1 carat diamond is ideal because it can fit within your budget without being visually overpowering. Premium diamonds of higher carat weights are also very rare.
Generally, anything above two carats is considered large for a ring, although some of our favorite celebrities like Mariah Carey and Lady Gaga have been seen sporting much, much larger rings.
Blue sapphires are the standard but pink and yellow colored sapphires are rising in popularity. A sapphire without any visible inclusions or chips can hold its price indefinitely.
Sapphires are the most valuable and rarest blue colored natural gemstones. They are a highly desirable gemstone due to their beautiful royal blue color, hardness (second only to diamonds), durability, and luster (sparkle from light performance within the gemstone).
As sapphires get bigger, their price-per-carat increases more and more, due to the rarity of larger stones.
No matter what, a well-cut diamond will show more brilliance, dispersion, and scintillation than a well-cut white sapphire. That means that diamonds will appear brighter (brilliance), have more colorful flashes (dispersion or "fire"), and sparkles of light (scintillation) than sapphires.
However, natural sapphires come in almost every color of the rainbow including pink, rose, violet, yellow, orange, green, blue-green, or white (colorless). The special color combination of pink-orange or orange-pink is known as Padparadscha sapphire, the rarest sapphire color, and a special rarity.
Sapphire shapes
The most common cuts are round, oval and cushion, though of course this is down to personal preference. The shape and cut work together to perfectly enhance the color, clarity, and shine of the gem.
No matter the cut, a 1-carat weight is a popular choice— it's the average diamond size for a typical engagement ring in the U.S., which can range between 1.08–1.2 carats, according to diamond consultants The Diamond Pro.
1 carat is absolutely fine. If you are comfortable spending at lot more money for a slightly larger stone, go for it. Prices increase rapidly as stone increases is size assuming the same Cut, Color,and Clarity.
Beyond being a perfect size (big, but not too clunky on your finger), the 1-carat diamond ring is a popular choice because it allows the wearer to adorn a ring with side stones, like a 3-stone ring, leaving room for extra diamonds to accentuate the center stone without overcrowding or overwhelming it.
One of the decisions to be made when considering the purchase of an engagement ring is how many carats should the ring be? The average according to The Knot (a research company and website for all things wedding) is 1 to 2 carats. There is no rule. Developing a budget is always a good place to start.
As one might expect, as the carats, or weight, of a diamond increases, so does the price. The larger the carat size, the more dramatically the price can increase. This is because it is more difficult to find larger diamonds than it is smaller ones, and so the larger ones are worth considerably more.
A stone cut too shallow will look larger on a finger, but it may not reflect light well or look as vibrant. A higher carat weight diamond that's cut too deep, will actually look like a much smaller diamond.
From what we've learned, it would seem that there are a few options for the 'best' sapphires. Too dark and a sapphire loses value, but too light, and it also loses value. The sweet spot for sapphires therefore, is a mid-range blue colour that holds its own when faced with intense light.
Sapphires are actually quite hard and score 9 on the Mohs hardness scale. "Second only to diamonds," Earlam-Charnley points out. This means that sapphires are suitable for everyday wear. "A sapphire should last a lifetime and can be passed down for generations."
However, if you're wondering which shapes are most popular for sapphires, we have an answer: oval, round, cushion, and emerald. The cushion cut is particularly popular for sapphires, as this cut tends to show color very well. This can enhance the beautiful hue of a sapphire.