Pearl:
An ancient organic gem. Mainly produced in mollusks such as pearl shellfish and Pinctada; The calcium carbonate-containing mineral (aragonite) beads produced by endocrine function are composed of a large number of tiny aragonite crystals. According to the research of geology and archaeology, there were pearls on the earth 200 million years ago. The international gem circle also lists pearls as lucky stones for June birthday and commemorative stones for 13 and 30th wedding anniversary. Pearls with magnificent colors and elegant temperament symbolize health, purity, wealth and happiness, and have been loved by people since ancient times.
Nanyang pearl:
Nanyang pearls refer to natural or cultured seawater pearls produced in countries along the South Pacific. Major pearl producers include Australia, India, Japan, Indonesia, Philippines, Myanmar and Thailand.
Black pearl:
Tahiti Black Pearl (also known as Tahiti Black Pearl) is produced in coral atolls of French Polynesia in the South Pacific. Mother-of-pearl is a black butterfly shell that secretes black nacre. The beauty of black pearl lies in its colorful colors on the black tone of the sky, and the most appreciated colors are peacock, deep purple, navy and other rainbow colors. Her strong metallic luster changes with the rotation of the pearl, which is far beyond the comparison of other color-changing pearls. Generally, the diameter of black pearls is 8 to 16mm. From round to pear-shaped or even banded.
Tahiti black pearl gives people a vivid style.
This kind of pearl is traditionally called black pearl, but their color series consists of metallic silver-the color of pencil lead. In this series of colors, they are refracted by light, accompanied by overtones of different colors, such as green, deep purple or sea blue.
Pearl morphology:
1. Zhu Yuan
Refers to round pearls, which are divided into three types according to roundness, namely round pearls, round pearls and nearly round pearls.
The right ball refers to the ball with the best roundness, which is also commonly known as the walking ball in business. The ratio of the difference between the maximum diameter and the minimum diameter to the average straight diameter is less than 1%. A round pearl refers to a pearl with a very round shape, and the percentage of its diameter difference is between 1%-5%; Near-round pearls refer to pearls that are close to round pearls in morphology, and the percentage of diameter difference is between 5%- 10%.
2. Oval beads
Refers to the oval pearl whose length-diameter ratio is greater than 10%. It can be further divided into short ellipse and long ellipse according to the percentage of long and short diameter difference, and the percentage of long and short diameter difference of short ellipse is10% ~ 20%; The percentage of the diameter difference of the long ellipse is greater than 20%.
3. Flat beads
Refers to a plane shape with one or two sides, such as oblate circle, oblate ellipse, pie shape, diamond shape, square, etc. This kind of pearl is most suitable for making pearl beads.
4. Ma Bizhu
It is a kind of semi-bead, also known as Mabeizhu, steamed bread bead and semi-round bead, also known as Mabeizhu.
5. Heterogeneous beads
In addition to round beads, oval beads and marbi beads, there are many pearls with different shapes. Pear-shaped pearls, drop-shaped pearls, rice-shaped pearls, potato-shaped pearls, bean-shaped pearls and other pearls are collectively called shaped pearls in business.
Evaluation criteria:
Look at the light:
The so-called "bling", luster is the soul of pearls. Pearls that are dull and shimmering lack aura. Look at the light, put the pearl flat on a white soft cloth, and you can see the warm luster of the pearl overflowing; Looking at the light, a good pearl can see colorful iridescence, rich in layers, metallic in spherical surface, and even reflect people's pupils. Especially bright pearls can be classified as Grade A, followed by Grade B. ..
Gloss grade
The extremely strong A-reflected light is particularly bright, sharp and uniform, with a mirror-like surface and clear image.
Strong B reflected light is bright, sharp and uniform, and the image is very clear.
C reflected light is bright, and objects can be seen on the surface.
Weak D reflects light weakly, and the surface can illuminate the object, but the image is blurred.
circular degree
"You get what you pay for" and "Pearls are round and smooth". The rounder the pearls, the more beautiful they are, which is in line with the aesthetic habits of China people. Large round pearls show the beauty of the full moon. Glossy, creating a hazy artistic beauty. The percentage of the difference between the longest diameter and the shortest diameter of a pearl is ≤ 1% as the standard of perfect circle, the ratio of the difference between the diameters of pearls is ≤5% as the standard of circle, and the range from 5% to 10% is a near circle. But many times, you can see the circle with your own eyes.
(Diameter difference percentage%)
Perfect circle A 1≤ 1
Circle A2 ≤5
Closed circle A3 ≤ 10
Ellipse B > 10 can be a drop shape or a pear shape.
Flat C has symmetry, and one or both sides are almost flat.
degree of finish
The less acne, spots, scars, pits and spots on the surface, the better. Generally speaking, it is an acceptable standard not to see defects at a distance of 0.5 meters. The standard of Grade A is 100%. The surface is smooth, and no defects can be seen by naked eyes. Of course, it is difficult to see the flaw with a magnifying glass. One in a million.
With naked eyes, the surface is smooth and delicate, and it is extremely difficult to observe surface defects.
There are few flaws on the surface of Weixian B, which is needle-shaped and difficult to observe with naked eyes.
Xiao Xia C has tiny flaws, which can be easily observed by naked eyes.
Defect D has obvious defects, accounting for less than a quarter of the surface area.
The heavy defect e is obvious, which seriously occupies more than a quarter of the surface area.
As the saying goes, "seven pearls make eight treasures." Generally, pearls below 6 mm do not belong to the category of jewelry-grade pearls, and 7-9 mm pearls are generally loved by consumers. 10 mm pearls are rare, and only Nanyang pearls and black pearls are found above11mm. The higher the quantity, the rarer it is, and the price tends to increase exponentially. This standard is not difficult to see.
Color:
The colors of freshwater cultured pearls are divided into the following five series, including various body colors.
A) White series: pure white, milky white, silvery white, porcelain white, etc.
B) Red series: pink, light rose, light purple, etc.
C) Yellow series: light yellow, beige, golden yellow, orange yellow, etc.
D) Black series: black, blue-black, gray-black, brown-black, purple-black, brown-black, iron-gray, etc.
E) Others: purple, brown, cyan, blue, brown, purplish red, green yellow, light blue, green, bronze, etc.
Freshwater cultured pearls may have associated colors, such as white, pink, rose, silvery white or green.
There may be halo on the surface of freshwater cultured pearls, which can be divided into strong halo, obvious halo and halo.
Color description: body color description is the main one, accompanied color and halo color description are the auxiliary ones.