Carat (ct) – Unit of Mass for Gemstones
Carat (ct, कैरेट, ক্যারেট, کیریٹ, قيراط, quilate, Karat, карат, 克拉, カラット, 캐럿) is a widely recognized unit of mass used to measure gemstones and pearls. One carat equals 200 milligrams or 0.2 grams. This unit is standard in the jewelry trade and plays a crucial role in determining the value of precious stones like diamonds and sapphires.
Table of Contents
- Definition of Carat
- Symbol and Standardization
- Historical Background
- Uses of Carat
- Conversion to Other Units
- Importance in Jewelry
- Conclusion
Definition of Carat
A carat is a metric unit of mass equal to 200 milligrams or 0.2 grams. It is primarily used to measure the weight of gemstones and pearls. The higher the carat, the heavier and often more valuable the stone.
Symbol and Standardization
The standard symbol for carat is ct. It was standardized in 1907 at the Fourth General Conference on Weights and Measures. Prior to this, various regions used slightly different definitions.
Historical Background
The word "carat" originates from the carob tree (Ceratonia siliqua). Ancient merchants used carob seeds as a reference weight because of their uniformity. Over time, this evolved into a formal unit for weighing gemstones. Before standardization, the weight of a carat varied by region.
Uses of Carat
Carat is used globally in the gemstone and jewelry industry. Here are some examples:
- Diamonds: A 1-carat diamond weighs 0.2 grams.
- Pearls: Often measured in carats for consistency.
- Sapphires, emeralds, rubies, and other gems are also weighed in carats.
Note: In the gold industry, "karat" (with a 'k') is used to indicate purity, not weight.
Conversion to Other Units
Here are common conversions for the carat:
- 1 carat = 200 milligrams
- 1 carat = 0.2 grams
- 1 carat ≈ 0.00705 ounces
- 5 carats = 1 gram
Importance in Jewelry
In gemology, carat weight is one of the "4 Cs" that determine a diamond’s value—Carat, Cut, Color, and Clarity. The carat significantly impacts pricing, especially since larger stones are rarer. Even small differences in carat weight can change the price dramatically.
Conclusion
The carat (ct) is a key unit in the world of gems. It offers a universal way to communicate the weight of precious stones. Whether you're buying, selling, or studying gems, understanding carat ensures accurate and fair valuation. It's a small unit with a big impact.