Onyx/Agate is a kind of chalcedony mineral, often mixed with Opal and cryptocrystalline quartz ribbon block, hardness 6.5-7 degrees, specific gravity 2.65, the color is quite hierarchical. Having translucency or opacity. The original form of the three crystal system. Often dense mass-like and form a variety of structures, such as breast, grape, tuberculosis, etc., common for concentric circle structure. Chalcedony, which has different colors, usually has many colors, such as green, red, yellow, brown and white. According to patterns and impurities, it can be divided into Onyx, agate, agate, Castle agate and so on. Often used as playthings, ornaments, ornaments or playthings. Ancient agate balls are often seen in funerary objects.
There are many kinds of Onyx/agate, such as pictographic agate (agate natural patterns, agate screen stone, pictographic slices, pictographic agate, aquatic agate, marine chalcedony, scenic agate, pictographic agate, shadow agate, etc.), southern red agate, Warring States red agate, ice sugar agate, northern red agate, agate, agate, agate, agate, salt source, etc. Agate, silk agate, fire agate, Gobi agate, grape agate, wolf blood agate, Xinjiang Hetian agate seed, insect agate and so on.
Often dense mass-like and form a variety of structures, such as breast, grape, tuberculosis, etc., common for concentric circle structure. The colors vary depending on the type and amount of impurities contained. They are usually banded, concentric, cloudy or dendritic. White, gray, brown and reddish-brown are the most common colors, as are black, blue and other colors. Stripe white or near white. Waxy luster, translucent to transparent. Shell fracture. The hardness is 7, and the density is 2.6-2.7g/cm.
It is irregular, massive, nearly oblate and cylindrical. Red, orange red to crimson and creamy white. Streak white. Semitransparent. The surface is smooth and glassy, and some are more uneven and waxy. Lightweight, hard and brittle, fragile, cross-section can be seen to force point for the center of the concentric circle ripple, like a shell. With sharp edges and corners, the glass can be cut and scratched. Odorless and tasteless. Rapid friction is not easy to heat. Better quality, bright red and transparent.
Onyx/Agate has a long history. About 100 million years ago, underground magma erupted in large quantities due to changes in the earth's crust. As the lava cooled, steam and other gases formed bubbles. The bubbles are sealed up when the rocks freeze and form many holes. After a long time, the hole was immersed in silica containing solution and condensed into silica gel. The molten elements of iron bearing rock enter silica gel, and finally the silicon dioxide crystallized into agate.