Dushan jade knowledge
Dushan jade is a compact block with a known maximum block size of 1,500 kilograms. Glossy glass. Usually opaque, high-quality translucent. Due to the presence of color minerals and a variety of pigment ions, Dushan Jade's colors are complex and varied, summing up green, white, purple, yellow and variegated colors. Of these, more than 50% were variegated jade, 30% green jade, and 10% white jade. When the composition contains chromium, it is green or emerald; when it contains vanadium, it is yellow; when it contains iron, manganese and copper, it is pale red; when it contains titanium, iron, manganese, nickel, cobalt, zinc, tin, Purple and so on.
The characteristics of these five colors are as follows:
1. Baidushan jade is mainly milk white, and some have gray and pink shades. Delicate texture, hard and dense, shiny glass, a slight sense of transparency.
Variety: water white jade, white jade, lotus jade, black white jade.
2. Green Dushan Jade is mainly emerald green and emerald green. Fine texture, hard and dense, glass luster, transparent to translucent.
Variety: Green Tsui, Jade, Jade 3. Purple Dushan jade.
The dark greens have lavender spots on the shrimp-like texture. Fine texture, hard and dense, shiny glass, opaque.
Variety: Purple jade, bright brown jade.
4. Huangdushan jade is uniformly yellow-green or olive green. Fine texture, hard and dense.
Variety: Orange Jade 5. Variegated Dushan Jade Dushan Jade with two or more main colors, fine texture, firm and dense, glass luster.
Variety: Moyu, Cuibaiyu, Caihuayu, Wuhuayu, Yucaiyu, Banyu, Heihuayu.
Dushan jade is mainly used for carving various jade articles, and sometimes it is used as a ring face and beaded jewelry.
The color is good or bad, followed by pure green, green, blue-green, light blue-green, blue in water white, green white, dry white and mottled. The positive color and the homogeneous color are the top grades, while the opposite is the inferior quality.
The texture requires dense and delicate, no white bars, no cracks, no impurities, the stronger the gloss and the higher the transparency, the better. High quality people are translucent in the sun.
As Dushan jade is mainly used as a raw material for jade, the larger the block size, the better. The general requirements should be more than 1 kilogram or more, and individual products made of jewelry can be lowered.
The technical requirements for Dushan Jade raw materials are divided into four levels:
Special grade: The color is pure green, green, blue-green, blue in white, green and white; fine texture is no white ribs, no cracks, no impurities, no cotton willow; block size is more than 20 kg. 1596
A: The color is white, white, green, uniform color; fine texture, no cracks, no impurities, block size of 20 kg or more.
Grade II: The color is white, green, with variegated colors; fine texture, no cracks, no impurities, block size is more than 3 kilograms; pure green, green, blue, green, blue, white, green and white, no white ribs, no cracks, No impurities, block size of 20 kg or more.
Grade 3: Brighter in color, finer in texture, slightly contaminated and cracked, with a block size of 1 kg or more.
The technical standards for the identification of Dushan Jade by quality requirements and technical standards are as follows:
Gloss: Glass sheen.
Cleavage: No Mohs hardness: 6-7
Density: 2.7-3.09g/cm3 General 2.9g/cm3
Photometric characteristics: Heterogeneous aggregation Polychromaticity: No refractive index: 1.560-1.700
Ultraviolet fluorescence: no to weak, blue and white, brown yellow, brown red Enlargement inspection: fiber granular structure, blue, blue-green or purple stain special optical effects: no Dushan jade and imitation products have been identified:
Emerald hardness 6.5-7 Specific gravity 3.25-3.36 Handcuffs are heavier than agate, refractive index 1.64-1.66
Texture: Hard and delicate, often cuihua composition minerals: jadeite nephrite hardness 6-6.5 specific gravity 3.2-3.9 rate 1.6-1.64
Texture: very hard and delicate composition of minerals: tremolite, Yang Qi Dongling stone hardness 7 proportion of about 2.66
Texture: The brittle handkerchief is heavier than agate, refractive index 1.54-1.55
Composition of minerals: Quartz, Lithium mica, rarely have the same ribbon structure as agate.
Saitama hardness 2-6 refractive index 1.53-1.57 hardness changes, usually about 4 composed of minerals: serpentine, the color is rarely the same strip with agate structure.
Glass imitation jade glass is uniform in color, contains bubbles of different sizes, has a shell-like shape, and has a lighter weight.
Quartzite rock is a glass sheen with strong graininess and transparency is stronger than Dushan jade.