Yu is considered to help a person, but in contact with it. Yu said that to enhance the feeling of cool and purify the thoughts, quiet the mind and induce meditative state. It is also believed to cause frequent handling of jade stones grow more beautiful luster. According to a Chinese proverb, "Jade is cool because it comes from the essence of a clear mountain stream." Science "says Jade is a cool feeling, because it is a non-conductor. Product Details - Shape / Type: Ring / Charm - Material / Gemstone: Emerald / - Shipping / Handling: Standard international shipping (10-18 days delivery) - Level / Type: 100 A / A type / A type - Country of Origin: China - Refractive index: 1.66 - 1.67 - Specific gravity: 3.33 - 3.34 - Colors and varieties: green, icy varieties - Weight (g / CT): ~ ~ 2.6 g / 13 kt - Luster: vitreous luster - Surface texture: medium grain - Condition: Excellent