Identification characteristics of sapphire (1) Crystallization habit: sapphire belongs to a tripartite crystal system and has a hexagonal structure (2) refractive index: 1.762- 1.770 (3) birefringence: 0.008~0.0 10 (4). (7) Absorption spectrum: The absorption spectrum of blue sapphire often shows a band in the blue region. In some natural blue sapphires, a group of two or three closely adjacent bands can be seen in the blue area; Many green and gold sapphires have similar spectra. (8) Special optical effect: starlight effect, which will reflect charming six-shot starlight or twelve-shot starlight under light irradiation, and color-changing effect (9) Mohs hardness: 9( 10)SG (relative density): 3.99-4.00 (1kloc-0/) cleavage: no cleavage.
Color reasons: Ruby is mainly colored by chromium; Sapphire is mainly colored by iron.
2. Garnet can be divided into almandine series (mafic-almandine, almandine and manganese-almandine) and andradite series (calcium-chromium garnet, calcium-almandine and andradite).
* * * are all cubic gems, with glass luster and diamond luster on the crystal face and oily luster on the cross section. Transparent to translucent. Isotropic objects are neither polychromatic nor birefringent.
Personality mainly lies in the differences in main components, chromogenic elements, refractive index, hardness, density and so on. , not listed here.
3. Crystal, glass, Dongling stone, chalcedony, agate, etc. Gems belong to single crystals such as crystals; Emerald belongs to a polycrystalline aggregate such as agate and chalcedony.
4. China's four Yin Zhangshi are Zhejiang Changhua Bloodstone, Fujian Shoushan Shoushan Stone, Zhejiang Qingtian Stone and Inner Mongolia Balin Stone.
Features: (1) Bloodstone: Changhua Bloodstone can be divided into four categories: frozen ground, soft ground, hard ground and hard ground according to material composition, transparency, luster and hardness. First of all, the quality of bloodstone is distinguished according to the amount, shape and brightness of blood. Generally speaking, it is better to have more blood, fresh color and beautiful shape, while the blood is deep and heavy, and it is better to have thick blood or even patches. Blood volume less than 10% is average, more than 30% is medium and high grade, more than 50% is extremely rare, and more than 70% is extremely rare. According to the texture and blood color of bloodstone, it can be divided into: Dahongpao, glass jelly, Tian Huang jelly, sheep fat jelly and so on.
(2) Shoushan Stone: Tiankeng Stone
Also known as Shi Tian, the main varieties are Tian Huangshi, Tian Huang Frozen Stone, and many silverstone days. Some people call all the pit stones Tian Huangshi. Tiankeng stone has no roots and veins, is in natural form, has no obvious edges and corners, and is deposited in the lower layer of a field one or two meters deep. There are many appearances, red squares become tendons, and the texture has radish patterns. The texture is soft and moist, and yellow is the most precious. Tian Huangshi can be divided into upper half, middle half, lower half and lower half according to different producing areas.
Shuikengshi
There are more than a dozen varieties, such as crystal frozen stone, ox horn frozen stone, fish brain frozen stone and so on. It is produced in Kengtoudian Mountain, 2 kilometers southeast of Shoushan Village. There is an east-west vein at the source of the foothills stream. It has been soaked in underground water for a long time. Minerals are crystal clear, soft and pure in color, but generally small in size. Among them, crystal frozen stone, horn frozen stone and digging head stone are the most typical.
Shanjingshi
Refers to the primary ore of Shoushan stone in the rock, which is vein-shaped. Due to the high terrain, there is not much underground water, and the stone is slightly inferior to the puddle stone. Shankeng stone has a wide distribution range and a large output. Due to the different environment inside and outside the place of origin, the varieties are Alpine Stone, Ducheng Pit Stone and Shanbo Cave Stone. Among them, the hibiscus stone in Jialiang Mountain Stone, which is second only to Tianhuang, is the most precious.
(3) Qingtian Stone: Many commodity names are classified as 10 according to their appearance colors, such as blue jelly, fish jelly, fengmenlv, Huang Jinrong, okra and brown soy sauce jelly. In more than 100 categories of Qingtian stone, there are also things similar to Tianhuang, but with other names.
(4) Bahrain stone: bloodstone
Bahrain bloodstone refers to Bahrain stone containing red cinnabar, which is mostly transparent and translucent; There are red, vermilion, dark red, orange and so on. The shape of blood is flaky, massive, banded and star-shaped. All varieties are named after various "reds", such as sunset red, rosy clouds red, peony red and golden orange.
Fuhuangshi
Those whose main body is yellow, transparent and translucent belong to this category. Some varieties can also be subdivided according to hue and texture, such as chicken oil yellow, dense wax yellow and quicksand yellow. Among them, kumquat is comparable to Tian Huang.
talcum
All transparent, translucent, bloodless and yellow Bahrain stones are frozen stones, which is the most variety of Bahrain stones. Named after its main features, there are crystal, hibiscus jelly and sheep fat jelly.
Colored stone
All Bahrain stones that do not bleed, yellow or freeze belong to this category. The most obvious feature is opaque texture and rich colors, so the variety names are rich and colorful, such as safflower stone, yellow flower stone, coffee stone and wood grain stone.
Patterned stone
It refers to a kind of Bahrain stone, which has various natural scenery patterns and certain ornamental value, and can be named after the theme.
5. Pearl characteristics: The chemical composition mainly contains calcium carbonate. The chemical composition of pearl is: CaCO39 1.6%, H2O 4% and organic matter 0.4%. And contains a variety of amino acids: leucine (leucine), methionine (methionine), alanine (alanine), glycine (glycine), glutamic acid (glutamic acid), aspartic acid and so on. In addition, it also contains more than 30 kinds of trace elements, taurine, rich vitamins and peptides. Appearance characteristics pearls have various shapes, such as round, pear-shaped, egg-shaped, teardrop-shaped, button-shaped, arbitrary, etc., among which round is the best. Not an isotropic body. Colors are white, pink, light yellow, light green, light blue, brown, lavender, black and so on. , mainly white. White stripes. It has typical pearl luster, soft luster and rainbow color. Transparent to translucent. The refractive index is 1.530- 1.686 and the birefringence is 0. 156. There is no dispersion. The hardness is 2.5-4.5. The density of natural freshwater pearls is generally 2.66-2.78g/cm3, which varies from place to place. No cleavage. Good toughness. Under short-wave ultraviolet light, pearls show white, light yellow, light green and blue fluorescence, and black pearls emit light red fluorescence; There is yellow-white fluorescence under X-ray. Foam in hydrochloric acid. Character identification Natural pearls are spherical, oval, irregular spherical or rectangular, with a diameter of 1 ~ 6mm. The surface is white, yellowish white, light pink, light blue, etc. , with beautiful color and smoothness. Most decorated pearls have holes in the middle. It's hard and difficult to break, and the section has a layered feeling. It crackled with fire. No gas, slightly salty. The shape of cultured pearls is similar to that of natural pearls, but the surface gloss is weak. There are round sand or concha Haliotidis fragments in the center of the section, and a thin layer of real pearls on the surface. Only the nacre is used as medicine. No gas, slightly salty. But now the appearance of Hepu ecological pearls has greatly improved the quality of cultured pearls! Round particles, transparent luster, bright luster and hard texture are preferred.
Pearl maintenance:
1. The pearl surface lacks hardness, so it needs to be carefully stored. It is forbidden to scratch with a knife or hard objects.
2. Pearl is an organic substance, and its main component is calcium carbonate. Therefore, avoid contact with cosmetics, perfumes and any chemical substances, such as vinegar, orange juice, bleach, sulfuric acid, correction fluid, etc., so as to avoid damage to the pearl surface and loss of luster.
3. After wearing pearls, gently wipe the pearl surface with a soft wet towel to clean substances such as sweat or cosmetics.
4. Don't soak in hot water. Wash pearl ornaments, because it will lead to looseness.