The milk source color stone is produced in Yaoshan, Ruyuan Yao Autonomous County, Shaoguan City, Guangdong Province (there is no such stone species found in any area), so some people also call it “Yuyuan Yaoshan Color Stone”. This stone is gradually famous in the province and abroad for its rich and colorful colors. According to the preliminary analysis of relevant geological experts, the milk source color stone is an extremely rare geological rock classification group, which contains silicon, calcium, copper, iron, tin, antimony and other elements, and its hardness is 4 to 7 degrees.

Technical requirements for quality of milk source color stone (1) Stone requirements. The argillaceous siltstone produced from the protected area has a calcium content of 0.2% to 1.5%, a copper content of 0.005% to 0.5%, an iron content of 0.3% to 5%, and a sulfur content of 0.005% to 1.5%. Long quartz sand, fine quartz sand, silt, etc., hardness is above 4 degrees. (2) Process flow. Mining → material selection → design layout → cutting → grinding → polishing → waxing → with seat. (3) Classification of varieties. 1. According to color: oil stone, blue and white stone, purple stone, fire stone. (1) Oil color stone: rich in color and many changes, mainly containing red, yellow, green, black, white and gray colors. (2) Blue-and-white stone: The main color is green, green, blue, white, brown, and vermiculite. (3) Purple stone: purple, green lotus, brown, black, white, gray as the main color. (4) Firestone: The color is light blue and pinkish green, with red, vermiculite and black as the main color. 2. According to the grain line: the milk source color stone is divided into large flower stone, broken stone stone, tiger skin pebbles and phoenix tail stone according to the grain pattern. (1) Large flower stone: large pattern, thick texture lines, line width of more than 1cm. (2) Floral stone: medium and small patterns, fine lines, and line width below 1cm. (3) Tiger skin pebbles: consisting of small patterns of tiger skin striated markings. (4) Phoenix-tailed stone: It consists of a small pattern of phoenix-shaped markings. (4) Quality characteristics. 1. Sensory features: (1) Appearance: At least 5 kinds of colors, the color is natural color, the gloss value should be no less than 60 to 90 gloss units, with oil-like color, fine texture, hand lubrication, no cracks. (2) Styling: According to the material, the shape is diverse, small carved carvings, large stone carvings and ornamental stones can be made into a variety of shapes. 2. (1) Treasures: large patterns, including red, yellow, blue, green, brown, and other rich colors, strange patterns, profound picture, clear theme, textured lines with golden silk, high degree of silicification, hardness in More than 5 degrees. (2) Fine: Medium and above patterns, bright colors, rich changes, contrasting contrast, hardness above 5 degrees. (3) Excellent products: bright and colorful, the hardness is above 5 degrees. (4) Qualified products: There are more than 5 colors, and the hardness is above 4 degrees. 3. Physical and chemical indicators: hardness 4 to 7 degrees; compressive strength (Mpa) 6 to 40; external exposure index Iγ limit ≤ 0.6; internal exposure index Ira limit ≤ 0.8. 4. Safety requirements: product safety indicators must reach the national Product related regulations.

Apply to：
Producers within the scope of protection of the Ruyuan Caishi Geographical Indication Products may apply to the Quality and Technical Supervision Bureau of Ruyuan Yao Autonomous County of Guangdong Province for the use of the “Special Mark for Geographical Indication Products”, which shall be reviewed by the Guangdong Provincial Bureau of Quality and Technical Supervision. The General Administration of Inspection and Quarantine announced the approval. The statutory testing agency of Ruyuan Caishi is designated by Guangdong Quality and Technical Supervision Bureau.