What is "Carat" in precious gems?

The word "quilate" (abbreviated as "ct" or "Qts") is fundamental in gemology, as it represents the unit of weight measurement for precious stones. However, its origin and history are as interesting as the gems themselves.

The word carat comes from the Greek “kerátion”, which refers to the fruit of the carob tree. In ancient times, the seeds of this tree were known for their uniform weight, making them ideal for measuring precious materials accurately. Over time, this measurement spread from the Mediterranean to Arab and European civilizations, where the term evolved into “carat” in English and “quilate” in Spanish. Thus, a carob seed came to represent approximately the weight of a modern carat, that is, 0.20 grams.

Why use carob seeds?

The carob tree was not only common in the Mediterranean region, but its seeds exhibited uniformity in weight that facilitated their use as a "natural touchstone" for measuring precious stones. In fact, their weight is almost identical from seed to seed, varying minimally, which provided acceptable precision for the time. This characteristic meant that for centuries these seeds were used to calibrate rudimentary scales in markets for precious stones and metals.

Its evolution and establishment in modernity

As the trade of precious stones grew and became more global, it became necessary to standardize the measurement to avoid discrepancies between the different systems used in various regions. In 1907, the “General Conference on Weights and Measures” officially defined the carat as 200 milligrams, or 0.20 grams. Since then, this unit of weight has been adopted worldwide in the gem trade. It is understood that one carat is the common equivalent of 100 "points" of stone, just as 40 points (or 40pts) are 0.4 carats (0.4 Ct or 0.4 Qts).

This standardization not only helped to unify the valuation of gems in the global market but also facilitated the growth of an industry that depends on precision and consistency in measuring each stone. Thanks to this universal definition, gem buyers and sellers can be confident that a carat has the same weight in any country, which builds trust in transactions.

Importance of the carat in the value of precious stones

Nowadays, the carat weight is one of the key factors in determining the value of a gemstone. Although carat weight is just one of the characteristics that define value, along with color, clarity, and cut, it has a significant impact on the final price. Stones with higher carat weight are rarer and, therefore, usually more expensive.

However, we must not confuse weight with size. Two one-carat stones can have different volumes if their densities are different. A one-carat diamond may appear smaller than an emerald of the same weight due to the density of each mineral.

Beyond its commercial value, the carat of a gemstone has an emotional and cultural impact. For example, a one-carat diamond is often a symbol of significant commitment and personal value in Western culture. The choice of a stone of one carat or more not only reflects an aesthetic preference but also a statement of value and durability.

If you want to know its difference with the carat of gold, you can enter this link and if you want to expand on the topic of gold purity enter here.

Final conclusions

The term "carat" is not only a unit of weight for precious stones but also a symbol of the history and trade of jewelry throughout the centuries. From its origin in carob seeds to its modern standardization, the carat is a measure that ensures precision, trust, and value in the world of gems. Knowing this history allows us to appreciate each precious stone not only for its beauty but also for the rich tradition behind its value. Here at Napoleone Joyas we manufacture and market our jewelry with stones such as diamonds, emeralds, rubies, sapphires, moissanites, zircons, among others that you can consult with our advisors