In the broad category of jewellery, it can be divided into two major categories: gems and jade. Gemstones are single crystals of natural minerals, and jade refers to a collection of natural minerals. Although there are similarities in the composition of mineral components, physicochemical properties, accepted populations, and jewelry expressions, they are more different. This is what jewelers should know. The similarities and differences between gemstones and jade are shown in Table 3-1. The jade here mainly refers to jade and Hetian jade, which have a wide acceptance and a high market share. Gemstones are common gemstones represented by diamonds, red sapphires, emeralds, aquamarines, tourmalines and garnets.
1 Physical and optical properties are different.
The hardness of the gemstone is relatively high, and the Mohs hardness is usually greater than 7. The higher the hardness of the gemstone, the brighter the gloss after polishing. Diamond Mohs hardness is 10, its diamond gloss is the strongest gloss; red sapphire Mohs hardness is 9, strong glass luster; emerald, aquamarine Mohs hardness of 7.5 ~ 8, glass luster. The jadeite hardness of jade in jade is 6.5~7, glass luster; Hetian jade has a Mohs hardness of 6.0~6.5, grease luster-waxy luster. High-grade gemstones such as diamonds, red sapphires, and emeralds are usually harder than jade, so the gloss is stronger and brighter than jade.
Faceted ruby faceted ruby
2 The characteristics of mineral components and chemical components are different.
The gemstone is a single mineral crystal. Its mineral composition is a mineral variant of this mineral and its isomorphism. Although the chemical composition has a change in metal ions, the mineral composition and chemical composition are relatively fixed after the gemstone is determined. The physical properties are as follows. The refractive index, density value, hardness, visible light absorption spectrum, and infrared spectrum are basically unchanged. Jade is composed of various minerals, and the refractive index and density vary widely. For example, the dried green species in jadeite mainly contains sodium chromite, having a Mohs hardness of 5.5, a relative density of 3.4 to 3.5, and a refractive index of 1.74. The Mohs hardness of dry green jade is lower than that of ordinary jadeite (Jadeite Jade H is 6.5~7), and the density and refractive index are higher than jadeite jadeite (relative density is 3.33). The jadeite of omphacite (expressed as oily green) is also distinguished from jadeite jade (the most common type of bean, ice, white, green, emerald, etc.). The refractive index, hardness, and density of different varieties such as Baiyu, Jasper, and Moyu in Hetian jade also have a large range of variation, and infrared spectrum and visible light absorption spectrum vary depending on the variety.
Hetian jade (sub-material) carving crafts and Tianyu (sub-material) carving crafts
3 Gems are usually transparent minerals, and jade is mostly transparent – translucent, slightly transparent, opaque rocks, mainly translucent – micro-transparent.
Many jade varieties are opaque, such as taro in jade, white jade, sapphire, and jade in Tianyu. Because the gemstones are mostly transparent minerals, the inclusions can be observed. The inclusions can be used to study the material composition and temperature and pressure conditions. It is difficult to observe internal inclusions in jade.
Green garnet ring face green garnet ring face
4 “Beautiful” has different elements of appreciation.
Gemstones use their transparent nature to be processed to highlight the gemstone's color, fire, luster, and crystal clear. Jade uses carving points, lines, planes, and curved surfaces to express the texture, color, and crystal characteristics to highlight the warmth and color of jade. The most prominent elements of gems are color, fire and glow, and jade is texture, color and engraving.
5 Process performance is different.
In addition to being processed into a curved surface, the gemstone is processed into a combination of multiple facets in order to express special optical properties such as cat's eye, starlight effect, and can not be processed into a facet-shaped ring face due to the inclusion of cracks. Polyhedron type. The shape of the gemstone has a relatively fixed style. Generally, the jewelry of the gemstone is mainly composed of the ring face, the individual is small, and the weight is less than 1 carat to several tens of carats. The higher the gemstone, the smaller the common individual. Gemstone face is used to embellish precious metals (gold, platinum, etc.) into a variety of jewelry. Jade is mainly made up of craft carvings. The heads are large, and ornaments of several hundred grams or even several kilograms are common. They are carved into works of art and decorations, and various cultural connotations are expressed in line patterns. There are bracelets and craft ornaments. Big ornament that diamond gems don't have. Jade is the material for expressing art in the hands of jade carving masters.
6 There are differences in pricing methods.
Gemstones are priced by weight (weight) and jade is priced by piece.
7 There are differences in how the market is named.
Gemstones have traditional names such as rubies, sapphires, emeralds, and mineral names such as olivine, diopside, apatite, spinel, spodumene, garnet, and topaz. Wait. Because the mineral to which the gem belongs belongs to the attribute characteristics of the gem. Jade is usually different in terms of minerals, physicochemical properties, materials and characteristics. The people in the market are accustomed to using the place of origin to express the characteristics of the place. For example, Hetian jade, Kunlun jade, Luodian jade, Nanyang jade (Dushan jade), Xiuyan jade, and Afghan jade, Lantian jade, Huanglong jade, and Taishan jade named after the place of origin are named as jade varieties by the place of origin in the market. It is easy to cause confusion, and the nature of jade is not clear. The national jewellery jade naming standard stipulates that “the jade stone cannot be named by the place of origin”, and the jade stone that has actually been named by the place of production has corresponding identification standards.
8 Consumer groups are different.
The consumer groups of gemstones are world-wide and are widely known and accepted around the world. Diamonds are hard currency in the world. The consumer group of jade is mainly Chinese, and its acceptance surface has no gemstones, and the market scope is smaller than that of gemstones. When investing in gems and jade, be sure to familiarize yourself with the similarities and differences between them, which is instructive for what kind of variety you decide to buy.