Agate: Yes jade class gem. Ancient evil of them as sacred objects. It is rich in natural gas. Regulating the nervous, enhance memory, improves sleep, maintaining a strong effort with excellent effect. Two. Agate main ingredients are SiO2 (silicon dioxide), when the texture is very pure gray, if they contain a variety of pigments ions when they show red, black, blue, green and other colors, and has a deep or shallow ring-shaped structure. Agate general was transparent to opaque, refractive index of about 1.54, 2.60 specific gravity, hardness 7, vitreous luster, conchoidal fracture. Widely used since ancient times agate jade, ancient people often "pearl agate" to describe wealth; foreign mentioned in many legends give the wearer a pleasant agate and confidence, bringing dreams. Most of the natural red agate gray, there are very few for the black, red. Brazilian natural agate products include red, black onyx, agate flower of India, as well as high temperatures optimized three-color or multi-color agate. Optimized by high temperature high temperature accelerated onyx is buried in the ground needs of its thousands of years of physical and chemical processes in nature and natural agate no difference, and the associated processing methods have already been recognized in the international arena, gemstones color will not change the value of precious stones and similar natural products. Welcome to purchase this item, the purchase was successful, the seller news column, type the size of the ruler you need. ------------------------------------------------------------------------------------------------------------------ Product Details - Shape / Type: Ring /charm - Material / Gem: Agate / Black agate - Shipping/Handling for standard int'l shipping (10-18 days delivery) - Grade / Type: 100 Grade A / Type A / Class A - Origin: China - Refractive Index: 1.66 - 1.67 - Specific Gravity: 3.33 - 3.34 - Color Variety: black Color, Icy Variety - Weight ( g / ct ): ~ ~ 4.5 g / 13 ct - Size : Us 6-11 - Luster: Glassy Luster - Surface Texture: Medium Grain - Condition: Excellent 100% Satisfaction Guaranteed If you are not completely satisfied with our products , please send us an email and received within seven days from the date of your return for a full refund . No restocking fee will be charged .