Hetian jade is a single mineral rock composed of microcrystal aggregates, containing few impurity minerals, and the main component is tremolite. Gemmology in China points out that the Mohs hardness of nephrite is 6.0-6.5, and any jade with tremolite accounting for more than 98% is called Hetian jade, which contains tremolite, hornblende, actinolite and other mineral aggregates. The chemical composition of Hetian jade is hydrated calcium magnesium silicate, and the chemical formula is CA2MG5 (OH) 2 (Si4O11) 2; The following is a piece of Hetian jade with good quality:
Agate, also known as agate, Kate Ma, agate, etc. , is a chalcedony mineral. It is usually a banded rock block mixed with opal and aphanitic. Its main component is the cryptocrystalline structure of silicon dioxide, which is often layered repeatedly because it alternates with hydrated silicon dioxide (silicic acid). The following is a well-known agate stone:
The correct definition of jadeite is fibrous aggregate composed of pyroxene minerals, which are mainly jadeite minerals. Jadeite is a stony polycrystalline aggregate formed under geological action, which is mainly composed of jadeite or jadeite, sodium (sodalite) and sodalite (omphacite). The chemical composition of jadeite is sodium aluminosilicate-Aina [Si2O3], and the following are the best jadeite pendants:
It is precisely because of the essential differences in the mineral composition of these three kinds of jade that their basic physical forms are also very different, such as:
Gloss: Jade is glass luster, Hetian jade and agate are waxy luster, but good Hetian jade is oily luster;
Density: the density of jadeite is 3.33, that of Hetian jade is 2.96-3. 17, and that of agate is 2.6-2.7. Experienced people can tell by weighing the ingredients.
Hardness, jadeite and agate 6.5-7, Hetian jade 6-6.5, Hetian jade is soft;
Magnified observation shows that both jadeite and hetian jade are interwoven with fibers, and most products can clearly see cotton wadding, and jadeite can also see the typical characteristics of "fly wings" (so-called "emerald"). Hetian jade with good quality has poor permeability, fine crystal particles and a felt-like interwoven structure, but the luster of oil is stronger, while agate has a hidden crystal structure, and no "cotton wool" crystal characteristics can be seen whether it is transparent or not.
Typical characteristics: jadeite with fine texture and high seed water will have obvious fluorescence effect after polishing (as shown in the above picture), while jadeite with coarse seed water generally has "cotton wool" staggered inside; Hetian jade seed material is delicate and moist (as shown above), often with "skin", and some Hetian jade will have "waterline" inside; Most agates have more or less typical agate patterns, which is a typical feature that distinguishes them from many other jades.
The following are typical features of jadeite absorbent cotton:
The following are typical features of Hetian Jade Waterline:
The following is a typical agate pattern:
In a word, Hetian jade, agate and jadeite have their own characteristics, and it is easy to identify people who often play with them.