Sheep fat white is not pure white, but oily white. Its color is fat white (slightly light cyan, milky yellow, etc.). ), fine and moist in texture, good in greasiness and containing a small amount of impurities such as stone flowers. ? In white, some can be slightly yellow, and those with poor texture can also be slightly light gray in white.
The glow of suet white jade in candlelight is soft and yellowish, like congealing fat, delicate and moist with few flaws, and "white as fat".
The soft part is chicken bone white, the hard part is china white, and all parts are "aging". It is not as white as it used to be. This is not a problem, but the characteristics of unearthed ancient jade. After more than 2,000 years of water and soil immersion, the white sheep fat jade is hard and dense, and it is as warm as ever, which is its value and its value.
This kind of suet white jade, the white jade of Han dynasty, has "rice seepage" in its muscles, so it is difficult for future generations to imitate it and can only be made naturally. Blue and white jade in Ming and Qing dynasties has no "rice infiltration".
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Identification points of sheep fat white jade
1, Shuitouzu-Shuitou and Lingtu are the names of Yutu. In tremolite jade, the thickness is usually 2mm as the standard, while white jade is translucent-opaque in this standard, and the head of suet jade is enough to show its translucency.
2, the color is suet white-suet white is not pure white, but white with oily luster, some can reveal a slight yellow, and poor texture can also reveal a slight light gray tone in white.
3, oily-suet jade in people's hands in the process of constant touch, will naturally produce a kind of "oily" feeling on the surface of jade, in some hetian jade fine white jade also has this phenomenon, when suet jade falls in the water, lift the body, can drop water without sticking, so oily suet jade is also very good, the so-called sponginess, that is, toughness.
4. Pure texture-the tremolite mineral content in sheep fat jade reaches 99%.
Sheep fat jade exists in the alteration area of surrounding rock. When the contact between granodiorite and dolomite produces a series of contact metamorphic rock series, dolomite becomes dolomite marble, and hydrothermal solution passes through the structural fracture channel of dolomite marble in the late magmatic period, and metasomatism occurs to form tremolite.
The surrounding rock has been eroded and deformed into three lithofacies: dolomite marble-tremolite dolomite marble-tremolite, and suet jade is produced in tremolite lithofacies.
5. Fine structure-tremolite in suet jade is aggregated in microfibril-like crystals.
The crystal size of tremolite can be measured under electron microscope and optical microscope. The fiber length (longitudinal direction) of tremolite in suet jade is 0.033-0.0 1mm, and the width (transverse direction) is 0.0006-0.001mm. These microfiber, fluffy and felt tremolite crystals are interwoven with each other to form a fluffy structure.
Microfiber, fluffy and felt tremolite crystal aggregates are characterized by not uniform extinction at the same angle under orthogonal polarization.
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