DIAMOND GUIDES
A Guide to Diamond Carat Weight
Carat weight is a key measure of a diamond’s size and mass, and one of the four essential attributes that define diamond quality—alongside cut, colour, and clarity—collectively known as the 4Cs.
Historically, the term “carat” originates from the use of carob seeds as natural counterweights on balance scales, due to their relatively uniform size and weight. This ancient method laid the foundation for today’s standardized unit of measurement in the diamond industry.
This Fuster Guide offers a refined exploration of diamond carat weight, detailing its definition, significance in the selection process, and an overview of the carat weight scale to assist in making an informed and confident choice.
What is a diamond carat?
Carat is the standard unit used to measure a diamond’s weight, with one carat equivalent to 200 milligrams or 0.2 grams. At Fuster, every diamond—whether a delicately proportioned gem under one carat or a rare stone exceeding 100 carats—is meticulously selected and masterfully cut. Each embodies the House’s enduring commitment to excellence, precision, and timeless beauty.
What is the diamond carat weight scale?
The carat weight scale is the standard measure for evaluating the weight of a diamond, with one carat equal to 100 points. For instance, a diamond weighing 0.50 carats corresponds to 50 points, while a 1.00 carat diamond equates to 100 points. Carat weights can range from delicate fractional sizes to remarkable stones of hundreds of carats, each offering distinct appeal and rarity.
- Under 0.50 Carats
Diamonds in this range are most commonly featured as accent stones in fine jewelry designs. For example, a 0.25 carat diamond may beautifully complement a center stone in a classic engagement ring setting. - 0.50 to 3.00 Carats
This carat range is highly sought after for engagement rings and signature jewelry pieces. A 1.00 carat diamond is widely recognized as a timeless and elegant standard for center stones. - 5.00 Carats and Above
Diamonds of 5 carats or more are considered exceptionally rare. These stones are typically reserved for high jewelry creations, where their size and presence elevate a design to extraordinary levels of luxury.
An overview of the Gemological Institute of America (GIA) diamond carat weight grading system
Established in 1931, the Gemological Institute of America (GIA) is a globally respected non-profit organization committed to public benefit. Renowned for its pioneering gemological research, the GIA safeguards consumer trust through rigorous gemstone analysis, expert education, and independent grading. Its standards are recognized as the benchmark of excellence in the industry.
At the heart of GIA’s legacy is its development of a standardized carat weight classification system, designed to ensure consistency and precision in diamond grading. This internationally recognized scale is as follows:
- Melee Diamonds: Less than 0.18 carats
- Small Diamonds: 0.18 to 0.99 carats
- Medium Diamonds: 1.00 to 1.99 carats
- Large Diamonds: 2.00 to 2.99 carats
- Very Large Diamonds: 3.00 to 3.99 carats
- Exceptionally Large Diamonds: 4.00 to 4.99 carats
- Rare Diamonds: 5.00 to 10.00 carats
While carat weight is a key indicator of a diamond’s size, it is not the sole determinant of its beauty or value. A diamond’s true brilliance emerges from the harmony of the 4Cs—Cut, Color, Clarity, and Carat Weight. Among these, the quality of the cut plays a pivotal role, influencing how the diamond reflects light and ultimately how it dazzles to the eye.
The GIA continues to verify the origin and integrity of the world’s most exceptional gemstones, including those used by prestigious houses like Fuster, ensuring that every certified diamond is worthy of the trust placed in it.
