According to this standard, China has a lot of jade. For example, Xiuyu is a beautiful collection of mineral serpentine. Not all serpentine minerals can be turned into jade. There are others like dushan jade and Nan Yu.
In fact, there are only two kinds of jade recognized internationally: jadeite and nephrite. Jade and nephrite here actually refer to two minerals. Jade is jadeite, and nephrite is hetian jade in China. Of course, other countries also produce nephrite. However, I want to emphasize that the Mohs hardness of nephrite and jadeite is actually 6-7, with little difference. Jade can be harder than nephrite when carving each other.
Jadeite is actually an aggregate of various minerals with jadeite as the main mineral, which can contain amphibole, feldspar, chromite, chromite, diopside and other minerals.
The mineral name of agate is chalcedony. The chemical composition is silicon dioxide. There are also many jade whose chemical composition is also silica, such as tiger's eye stone. However, agate will have very distinct concentric layered and regular banded lines, which are called agate lines.
The landlord said that these three things are smooth stones, because they are all polished, and there is no one that is not polished.
Let's talk about these three things first. Jade and agate belong to jade. They are different in color, specific gravity, luster and grain.
The specific gravity of agate is about 2.6, and that of jadeite is about 3.33.
This is a place where people without gemmological knowledge can easily separate the two.
References:
Interpretation of National Standards for Jewelry and Jade