GEMSTONE SPECIES - INORGANIC

Chrysoberyl refers to the non-phenomenal varieties of the chrysoberyl mineral, which do not exhibit the cat's eye effect or color change like its more famous counterpart, alexandrite. While not as rare or celebrated as alexandrite, this gemstone still holds significant value due to its clarity, durability, and brilliance. Among the popular types of chrysoberyl are Cat’s Eye Chrysoberyl and Alexandrite. 

Colour Causes:

--> The yellow to green color spectrum of chrysoberyl is attributed to its iron content.

--> Richer yellow or green hues in this gemstone are more sought after. 

Treatment:

Most chrysoberyl gemstones are untreated, as their natural brilliance and color typically do not require any form of enhancement.

Chrysoberyl Cat’s Eye, commonly known as Cymophane, is a captivating gemstone renowned for its sharp, luminous band of light that gracefully moves across the surface, resembling the slit eye of a cat—a fascinating phenomenon called chatoyancy. This cat's eye chrysoberyl effect is caused by parallel needle-like inclusions, typically made of rutile or other minerals. When this gem is expertly cut as a cabochon (which features a smooth, dome shape), these inclusions reflect light, creating a striking single bright band across the surface. Quality grading factors for cat's eye chrysoberyl include: the sharpness of the eye, where a more defined and centered eye indicates higher value; the colour, with rich, honey-toned variants being the most desirable; and transparency, where semi-transparent to translucent stones showcasing a strong eye are preferred. Additionally, eye movement plays a role; a good cat's eye appears to 'open and close' as the gem is rotated. Generally, untreated natural cat’s eye chrysoberyl is highly sought after, so it is important to be cautious of imitations crafted from quartz or glass.

Alexandrite is a valuable variety of chrysoberyl, renowned for its remarkable colour-change phenomenon. Often described as "emerald by day, ruby by night," this unique gemstone exhibits a striking colour change based on lighting conditions. Under daylight or fluorescent light, alexandrite shifts from rich green to bluish-green, while in incandescent or candlelight, it transitions from red to purplish-red. This captivating change is attributed to complex light absorption due to trace amounts of chromium in its crystal structure. The most valued trait of this gemstone is its strong, dramatic colour change, while size also plays a significant role, as large stones are extremely rare and highly priced. The origin is another crucial factor, with Russian stones being considered the finest examples of chrysoberyl. Most alexandrite stones are typically untreated, although clarity-enhancing treatments are sometimes applied. Additionally, another fascinating variety within the chrysoberyl family is cat's eye chrysoberyl, which exhibits a unique optical effect.