A COMPREHENSIVE GUIDE TO

diamond carat weight

what is carat weight?

Diamond carat is a unique measurement unit that holds the key to determining a diamond's weight.

A carat is the standard unit of measurement for the weight of diamonds and gemstones, equal to 200 milligrams or 0.2 grams.

Carat weight is divided into 100 points, allowing precise measurements (e.g., a 0.75-carat diamond equals 75 points).

The word “carat” comes from the carob seed, which was historically used as a weight standard by ancient gem traders due to its uniform size. This method was widely practiced across the Mediterranean and the Middle East. As diamond trade expanded globally, the need for a standardized measurement grew. In 1907, the metric carat was established, fixing 1 carat as 200 milligrams. This consistency simplified international diamond trading and remains the global standard today.

carat vs. size: what's the difference?

The size of a diamond, in terms of its carat weight, does not directly correlate with its physical dimensions or appearance.

Carat refers strictly to the weight of the diamond.

Size refers to the physical dimensions or appearance of the diamond when viewed face-up.

While carat weight provides a general indication of a diamond's size, it's important to note that other factors such as cut quality and shape also significantly affect its visual presence.

how is carat weight measured?

Diamond carat weight is measured precisely using a specialized scale sensitive to tiny increments, typically to the nearest hundredth of a carat (0.01 ct). This ensures accuracy in determining the diamond's weight, directly influencing its value.

factors affecting apparent carat weight

Shape and Cut: Different diamond shapes (e.g., round, princess, emerald) and cuts (e.g., brilliant, step cut) can affect how carat weight is distributed. Some shapes may appear larger for their carat weight due to their cutting style and depth proportions.

Setting and Design: The setting of the diamond (e.g., solitaire, halo, three-stone) and its design can influence how large the diamond appears. Settings that enhance light reflection and complement the diamond's shape can make it seem more substantial.

Proportion and Depth: Diamonds with ideal proportions and depth are cut to maximize brilliance and light performance. Well-cut diamonds may appear larger than those with deeper or shallower cuts of the same carat weight.

what is diamond equivalent weight?

Carat is the standard unit of measurement for a diamond's weight, but moissanite is typically lighter than diamonds by approximately 10%. For example, a 6.5mm round diamond weighs 1.0 carat, while a 6.5mm round moissanite weighs about 0.88 carat. Moissanite measurements are often expressed in millimeters alongside their diamond equivalent carat weight (CT DEW) to mitigate confusion. This ensures that a 1-carat round diamond and a 1-carat round moissanite have the same physical size.

tips for enhancing the perceived size of a stone

Choose an Elongated Shape: Shapes like oval, marquise, or pear appear larger than round diamonds of the same carat weight due to their elongated forms.

Opt for a Halo Setting: Surrounding the center stone with smaller diamonds creates the illusion of a larger diamond while adding sparkle.

Select a Slim Band: A thin band draws attention to the diamond, making it appear larger in proportion.

Prioritize Cut Quality: A well-cut diamond reflects more light, making it appear brighter and larger.

carat weight FAQs

Does carat weight determine a diamond’s quality?

No, carat weight only measures a diamond’s size. Factors like cut, color, and clarity are equally important for overall quality and brilliance.

Is a larger carat weight better?

Not necessarily. A smaller diamond with excellent cut quality can outshine a larger diamond with poor proportions or clarity.

How can I save money on carat weight?

Opt for slightly below popular benchmark weights (e.g., 0.90 instead of 1.00 carat) to save significantly while maintaining a similar visual size.

Why do diamonds of the same carat weight look different in size?

The diamond’s shape, cut proportions, and depth-to-table ratio influence its face-up size.