Inclusions in Emeralds
Understanding Inclusions In Emeralds
The inclusions in emeralds are sometimes referred to as “jardin,” or “garden” because they can resemble moss or plant foliage. Emeralds with many inclusions should be treated with care and protected from direct blows or thermal shocks. Inclusions are a natural consequence of crystal growth. Emerald inclusions vary with their source and may be used as a diagnostic tool for assessing the country of origin. Although fractures and liquid inclusions are the most frequent, inclusions typically found in emeralds include any of the following:
Included Crystals – Included crystals are light, dark, transparent or opaque minerals trapped inside a stone. In emeralds, you can frequently find minute crystals of quartz, calcite, mica, pyrite, halite, tourmaline, and apatite, for example.
Liquid Inclusions – Liquid or fluid inclusions are liquid-filled spaces or cavities within a gemstone.
Two-and Three-Phase Inclusions – Two-phase inclusions are the combination of a liquid filled cavity and a small bubble of gas. Three-phase inclusions are a liquid filled cavity containing both a crystal and a gas bubble. The latter are particularly indicative of emeralds from Colombia.
Needles – Needles are long thin crystals. In emerald, these include fibrous tremolite needles characteristic of emeralds from Zimbabwe, and actinolite needles characteristic of emeralds from Siberia.
Growth Tubes – Growth tubes are hollow spaces or tubes that are a byproduct of crystal growth.
Fractures – Fractures refer to fissures and cracks in a gemstone. Emeralds frequently have many fractures. Experts have differing opinions about what causes these fractures. Some believe that they are a natural byproduct of the crystal formation process, and others believe they are caused by harsh mining techniques. In general, African emeralds are known to have fewer fractures than stones from other locations. Most emeralds are treated with oils and resins to hide unsightly fractures. Care must be taken in cleaning these stones, because the oil can be removed.
Fingerprint Inclusions – Fingerprint inclusions are networks of tiny liquid-filled tubes that resemble human fingerprints. Fingerprints are formed when emeralds recrystallize or partially heal a fracture zone.
Color Zoning – Color zoning refers to areas or bands of alternating color within a gemstone. Colombian crystals often exhibit color zoning. Many have more intense color at or near the surface of the crystal.
Inclusions are responsible for the star-like pattern seen in trapiche emeralds. Trapiche is the Spanish word for the cogs of the sugar cane mill. When these unique emeralds were first discovered in Colombia, the miners thought that the rays of the star looked like the gears used to crush cane in a sugar cane mill.
Trapiche emeralds have a hexagonal center crystal from which six segments have grown outward. A fine-grained mixture of colorless beryl and feldspar crystals typically fills the radial spaces between the segments.
Emeralds may occasionally exhibit a special optical effect called chatoyancy . This phenomenon is caused by oriented inclusions that are numerous enough to allow the cutting of a cat’s-eye stone–although this condition occurs more frequently in aquamarine or heliodor than emerald.
Just as certain inclusion types can indicate a particular origin location, many have attributed levels of inherent quality based on the region where an emerald is found. On the following page, we unravel the truth behind the connection between Source & Quality.