The Cat's Eye gemstone, also known as "Lehsunia" or "Chrysoberyl Cat's Eye," is a unique and mesmerizing gemstone recognized for its distinctive optical phenomenon known as "chatoyancy." This phenomenon gives the gemstone its name, as it resembles the slit eye of a cat. Below are some of the key features and details about the Cat's Eye gemstone:

### 1. **Chatoyancy Effect:**
   - **Appearance:** The most striking feature of the Cat's Eye gemstone is its chatoyancy, where a bright band of light moves across the surface of the stone, resembling a cat's eye. This effect is caused by the reflection of light from parallel inclusions, typically rutile fibers or other needle-like structures, within the gemstone.
   - **Orientation:** The cat’s eye effect is best seen when the stone is cut in a cabochon shape (a rounded, polished form without facets) and the effect is most pronounced when the stone is viewed under a single light source.

### 2. **Color:**
   - Cat's Eye gemstones are typically found in shades of yellow, green, brown, and honey-like hues. The color can vary depending on the type of mineral and the presence of various impurities.

### 3. **Hardness:**
   - On the Mohs scale of hardness, Cat's Eye gemstones, specifically Chrysoberyl Cat's Eye, have a rating of 8.5. This makes them durable and suitable for various types of jewelry.

### 4. **Varieties:**
   - **Chrysoberyl Cat's Eye:** The most popular and valuable type, Chrysoberyl Cat's Eye is often simply referred to as "Cat's Eye" in the gem trade.
   - **Quartz Cat's Eye:** This is a less valuable variety of Cat's Eye, where the chatoyancy effect is present in a quartz matrix.

### 5. **Origin:**
   - Cat's Eye gemstones are found in various parts of the world, including Sri Lanka, Brazil, India, and East Africa. Sri Lanka, in particular, is known for producing high-quality Chrysoberyl Cat's Eye.

### 6. **Astrological Significance:**
   - In Vedic astrology, Cat's Eye is associated with the planet Ketu (the South Node of the Moon). It is believed to bring protection, ward off evil, and enhance the wearer's intuition and foresight. People wear it to bring good luck and to protect against the evil eye and negative energies.

### 7. **Uses in Jewelry:**
   - Due to its striking appearance, Cat's Eye is often used in rings, pendants, and earrings. The gemstone is typically set in such a way that its eye-like effect is prominently visible.

### 8. **Symbolism:**
   - The Cat's Eye gemstone is often associated with attributes like discipline, concentration, and insight. It is believed to help the wearer focus and achieve their goals by warding off distractions.

### 9. **Value:**
   - The value of a Cat's Eye gemstone depends on the intensity and sharpness of the chatoyancy, the quality of the cut, the clarity, and the overall color of the stone. The more pronounced the cat's eye effect, the more valuable the gemstone is.

This gemstone is cherished both for its aesthetic appeal and its mystical properties, making it a popular choice for those seeking both beauty and spiritual benefits.