Emerald gemstones, belonging to the Beryl mineral family, are renowned for their stunning green color and exceptional beauty worldwide. Several factors, including shape, cut, color shade, color zoning, clarity, size or carat weight, and place of origin, contribute to the value of an emerald. Inclusions found in emeralds have a significant impact on their price. Let's explore the various types of inclusions in emerald gems and their influences.
Understanding Clarity in Emeralds
To comprehend emerald inclusions, it is important to understand clarity. Gemstones are generally classified into three clarity types: Type I, Type II, and Type III. Type I gems typically have no visible inclusions and are considered very clear to the naked eye. Aquamarine and topaz are examples of this category. Type II gems exhibit some visible inclusions, such as natural rubies and sapphires. In contrast, Type III gems, like natural emeralds, have a high amount of inclusions affecting their clarity.
Facts to Know: Emeralds have a Mohs scale hardness of 7.5-8, making them delicate and vulnerable. To enhance their durability, most emeralds undergo an oiling process. However, even without oiling, genuine emeralds are still more durable than human fingers.
Inclusions in Emeralds
Inclusions in emeralds are referred to as "Jardin," meaning "garden" in French. Just as both emeralds and gardens are creations of nature, the inclusions resemble moss or plant foliage inside the green gem, hence the term Jardin. No two sets of inclusions are identical, making them useful for distinguishing between similar gems.
Reasons for Inclusions
Inclusions in emeralds occur because they are formed by nature. During the formation of emeralds, various random elements blend together within the earth. Transparent emeralds are considered rare, as different inclusions arise in each origin. Inclusions also vary depending on the origin and can be used to assess the source of an emerald.
Types of Inclusions in Emerald Gems
While fractures and liquid inclusions are commonly found in emeralds, there are also unique combinations of inclusions, including:
- Liquid Inclusions: Liquid inclusions are frequently found in natural emeralds, filling cavities within the gem. They can be formed by gas bubbles, creating a two-phase inclusion, or by a gas, liquid, and crystal, resulting in a three-phase inclusion.
- Crystal Inclusions: Crystal inclusions in emeralds are naturally occurring crystals of other minerals within the stone. They can be found amidst a halo surrounding them, typically formed during the emerald's formation or due to differences in crystal melting temperature.
- Fractures Inclusions: Fractures, referring to fissures and cracks in the gemstone, are the most common type of inclusion found in emeralds. Their occurrence is believed to be a natural byproduct of the stone's formation process or a result of harsh mining techniques. To improve durability and clarity, emeralds with fractures are often treated with oils and resins.
- Colour Zoning: Color zoning refers to variations in colour within a stone. While less common in emeralds compared to other colored gemstones like blue sapphires, colour zoning can be observed in emeralds. One portion of the stone may exhibit a bright green color while another section displays a different, darker shade of green.
- Fingerprints: Fingerprints, resembling human fingerprints or wispy veils, can also be present in emeralds. These inclusions often occur with the presence of liquid and gas, making them two-phase inclusions. They can be thicker and more pronounced, but they contribute to the overall appearance of the gemstone.
- Needles: Needles are long, thin crystal-like inclusions found in emerald gems. They fall under the category of fingerprint inclusions but are hollow evolutionary tubes left over after the emerald crystal's formation.
- Phenomena: Occasionally, emeralds exhibit an asterism feature, displaying a star effect phenomenon known as chatoyancy. This phenomenon occurs when fine needles or tubes align parallel to each other, creating a cat's eye effect. However, phenomena should not be confused with trapiche emeralds, which result from the overall crystal formation rather than being a specific inclusion.
Important Considerations
Emeralds with numerous inclusions are more prone to damage or breakage and should be handled with extreme care. They are often lubricated with mild oils and cleaned using a soft cloth.
Understanding the types of inclusions and their influences on clarity enhances our appreciation for the natural beauty and complexity of emeralds.