Emeralds are prized gems admired around the world for their distinctive green color, associated with wealth and luxury. However, beyond their color, some emeralds possess special optical characteristics that increase their rarity and value. One such phenomenon is the “cat’s eye.”

In this article, we will explore what a “cat’s eye” is in emeralds, with a special focus on Colombian emeralds, known for their superior quality.

What is an optical effect in a Colombian emerald?

Colombian emeralds are recognized worldwide not only for their vibrant color but also for their clarity and the presence of certain optical effects that make them unique. An optical effect is a visual characteristic that appears in the gem under certain lighting conditions.

These effects are due to the way light interacts with the inclusions or crystalline structure of the emerald. Among the most valued optical effects in emeralds are the "cat's eye", the "asterism", and the "garden".

Types of optical effects in emeralds:

1. Asterism: An optical phenomenon that forms a star of light on the surface of the gem, usually visible when the stone is cut en cabochon.
2. Garden: Involves a network of inclusions that may resemble a small garden within the emerald.
3. Cat's Eye: This phenomenon, also known as chatoyance, is one of the most sought-after optical effects in emeralds.

What is a “Cat’s Eye” in a Colombian emerald?

The “cat’s eye” in a Colombian emerald is an optical phenomenon that produces a band of light passing across the surface of the gem, similar to the pupil of a cat’s eye. This effect is caused by the parallel alignment of fine inclusions, such as rutile fibers or cavities, that reflect light in a brilliant line when the stone is cut into a cabochon. Colombian emeralds with “cat’s eye” are especially valued due to the combination of their deep color and this rare phenomenon.

Famous emeralds with the “Cat’s Eye” effect:

1. The Fura Emerald: One of the largest emeralds found in Colombia, famous for its intense color and clear “cat's eye.”
2. La Gachala: Known for its clarity and impressive “cat's eye” optical effect.
3. La Muza: A Colombian emerald famous for its exceptional “cat’s eye” and purity.
4. La Magdalena: This gem stands out for its size and the sharpness of its “cat's eye” effect.
5. The Sapphire Queen: Although its name suggests a sapphire, this emerald is known for its “cat's eye” and bright green color.

Paula A. Bonilla

Social communicator and journalist from Sergio Arboleda University in Colombia. She is also a jeweler and is passionate about constantly learning about precious gems and national fine jewelry.

She currently works for one of the most important jewelry stores in Bogotá, Esmeralda by Love. This jewelry store has more than 40 years of experience and has 2 physical branches in the capital of Colombia, located in the city center.