Cheap price February Birthstone Garnet - Natrual Gems Yellow Garnet Round 3.0mm – Datianshanbian

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Garnet, called ziyawu or ziyawu in ancient China, is a group of minerals that have been used as gemstones and abrasives in the bronze age. The common garnet is red. Garnet English “garnet” comes from Latin “granatus” (grain), which may come from “Punica granatum” (pomegranate). It is a plant with red seeds, and its shape, size and color are similar to some garnet crystals.
The common garnets are classified into six types according to their chemical composition, namely, pyrope, almandine, spessartite, andradite, Grossular, and the variants are tsavorite, Hessonite, and uvarovite. Garnet forms two solid solution series: (1) red garnet iron aluminum garnet manganese aluminum garnet and; (2) Calcium chromium garnet calcium aluminum garnet calcium iron garnet. Garnet has no grade distinction in the world. The so-called “A’s” are distinguished according to personal views. The same garnet can tell different a numbers in different hands. [1]

Main components：

The chemical composition of garnet is relatively complex, and different elements form different combinations, so a series of garnet families with similar texture and image are formed. The general formula is a3b2 (SiO4) 3, where a represents divalent elements (calcium, magnesium, iron, manganese, etc.) and B represents trivalent elements (aluminum, iron, chromium, titanium, vanadium, zirconium, etc.). Common are magnesia aluminum garnet, which contains chromium and iron elements and is blood red, purplish red and maroon; The second is iron aluminum garnet, which is purplish red. The crystal with inclusion development can carve out four-dimensional starlight; Magnesium iron garnet is light rose purple red, which is one of the important varieties of garnet gemstones; Calcium aluminum garnet contains trace vanadium and chromium ions, so it is called a top-grade green variety.
Due to the similar radius of trivalent cations, isomorphic substitution is easy to occur between them. Divalent cations are different. Because CA has a larger radius than mg, Fe and Mn plasma, it is difficult to replace it with isomorphism. Therefore, garnet is usually divided into two series:
(1) Aluminum series: mg3al2 (SiO4) 3 － fe3al2 (SiO4) 3 － mn3al2 (SiO4) 3
It is a isomorphic series composed of divalent cations such as Mg, Fe and Mn with small radius and trivalent cations such as al. Common varieties include magnesium aluminum garnet, iron aluminum garnet and manganese aluminum garnet.
(2)Calcium series: ca3al2 (SiO4) 3 － Ca3Fe2 (SiO4) 3 － ca3cr2 (SiO4) 3
(3)It is a isomorphic series dominated by divalent cation CA with large radius. The common ones are calcium aluminum garnet, calcium iron garnet and calcium chromium garnet. In addition, the lattice of some garnets is also attached with OH ions to form aqueous subspecies, such as water calcium aluminum garnet. Due to the extensive isomorphic substitution, the chemical composition of garnet is usually very complex. The composition of garnet in nature is usually the transition state of isomorphic substitution, and there are few garnets with end member components. [2]