Cat's eye gemstone, known for its distinctive optical phenomenon called "chatoyancy," is highly valued both in jewelry and for its purported metaphysical properties. Here are its key features and benefits:

Features:
1. Optical Effect: Exhibits a striking "cat's eye" effect, where a thin band of light appears to move across the surface of the stone, resembling a cat’s eye. This effect is due to needle-like inclusions or fibers within the stone.
2. Color: Available in various colors, including brown, green, yellow, and gray, with the most famous being the golden-brown hue of chrysoberyl cat's eye.
3. Hardness: Depending on the type, cat's eye gemstones can vary in hardness. For example, chrysoberyl, a common type, has a hardness of 8.5 on the Mohs scale, making it quite durable.
4. Clarity: Typically transparent to translucent, with the cat's eye effect being the primary feature rather than clarity.

Benefits:
1. Astrological Significance: In Vedic astrology, the cat's eye is associated with the planet Ketu. It is believed to bring success and protection, enhance intuition, and help with overcoming obstacles.
2. Healing Properties: Some believe that it can aid in mental clarity, boost self-confidence, and promote emotional balance.
3. Protective Qualities: It is thought to offer protection against negative energies and misfortune, providing a shield to the wearer.
4. Unique Appearance: The distinctive cat's eye effect makes it a standout choice for jewelry, adding a unique and eye-catching element.

Cat's eye gemstones are valued for their distinctive optical properties and are often chosen for their perceived spiritual and protective benefits.