AGSL:

American Gemological Association Laboratory, the authoritative diamond testing institution in the United States. 7s； V. Q4 F；; r+ }6 c* L) O

AGTA:

American Gem Trade Association, American Jewellery Association.

Antwerp cutting Antwerp cutting machine 6 z. l5 B$ o8 M! @3 i

Antwerp diamond craftsman's craft is recognized as the best in the world. In Antwerp, every day, thousands of workers go all out to get the famous quality mark Antwerp, that is, "Antwerp". Belgium also has a large number of diamond designers, who often hold diamond design competitions, such as the biennial Diamond High Council Award Competition, to encourage the emergence of new diamond design works.

Ascher cut diamond square cut.

Long strip and long step

Rectangular diamond with stepped cutting surface. If the longer side gradually narrows, it is called a sharp step.

Bar setting bar inlay? 5 ^- p % B4 b & amp； l7 k！ L

Diamonds are separated by metal and tightly fixed by left and right metal bars.

Baryon cutting

The cutting has a traditional stepped cutting crown and an improved bright cutting pavilion. In addition to the Senkaku, a square-cut diamond has 62 facets.

Beard fissure

Fine cracks that may occur during grinding. Slight cracks can be completely removed after re-grinding. :[& amp； U" k+ D，w% N: s- [

Bezel inlay1f1m 9 \ 7r3o+gt *}-i3c.

Diamonds in this mosaic technique are completely surrounded by precious metal edges shaped like photo frames.

Defect surface defect) z0 F- ]/ H( p" l" l

Including surface flower marks and stains, mushy scars caused by improper polishing, fine scratches on the surface and so on.

Brilliant 0 y1a. z * z 7n 8 b4y &； @

White light intensity of total reflection of light on diamond. It is closely related to tangent ratio and symmetry. % i' b，c & ampM5 Q( ~。 l

Bright cut

[Through scientific appraisal, the open cut reflects most of the light, which is also known as the brightest and liveliest cut. The most common brilliant-cut round diamonds have 58 facets, and there are other shapes, such as heart-shaped, oval, olive-pointed and pear-shaped brilliant-cut diamonds. -K # S2 y . m； z( K I

Bruising will leave a mark. y！ }: France, England

Traces left by the impact of external forces on diamonds. + t n，H“| 2]7 o6h！ H5 p$ R0 V

carat

The word carat comes from the seed of a plant called carob, which was used to measure weight in ancient times. One carat is 200mg, 142 carat is one ounce, carat can be further divided into 100 minutes and 1 carat, and half carat diamond is 50 cents (about 100 mg).

The cavity is empty, $ Y! g * X)C； a4 J，q E# r% i4 W3 y

A large and deep irregular crack in a diamond. % B8 R3 S( q2？ 5 r: {2 K

Channel setting slot plug-in

Often used to set a row of small stones with the same size rules. This inlay technique uses two pieces of metal to fix the gem from both sides. Used for setting round, narrow square and square gems. Groove inlay is like a railroad track with diamonds in the middle.

Characteristics of diamonds:? 4 E； z/ M5 C

Natural growth traces and artificial defects of diamonds.

Clarity classification

Every diamond contains natural inclusions, just like natural birthmarks, and the quantity, size, shape and color of these inclusions determine the purity and uniqueness of a diamond. As the name implies, inclusions are hidden in diamonds, which can be different colors: white, black, colorless, even green or red. Therefore, it is necessary to classify the internal and external characteristics of diamonds under the magnifying glass of 10 times. & ampw* m# z9 ~' }$ v# H

Cleavage fissure

A small hole in the waist of a diamond. 2 b# r) V: ~ D( ~9 H- ` t

cloud mass

The natural inclusions in diamonds are hazy milky white with no clear boundaries.

Cluster Settings Group Embedding

The main stone is surrounded by smaller associated stones, so many smaller diamonds can be combined into a larger and more beautiful ring. 6 Z- a2 h( y5 g) j2 d 1 v

Color classification' k&; `，e & ampx9g； I

Using colorimetry, the colors of diamonds are classified under specific circumstances.

Crystal internal texture! c" h) O2 u 1 a) m/ c

The natural crystal surface inside a diamond. 2 Q( M 1 n4 T+？ 0 ] 1 t

Crown crown +d2 b+ x4 t% D6 C, P! Engineering dollar Z+ t

There are 33 facets above the waist.

The crown ratio has an aspect ratio of 5 ~/ R5 Y/ w; C: I4 i0 k

The percentage of crown height relative to average diameter is calculated as follows/^* Z! K9 n .[& amp； I

Width-height ratio = crown height/average diameter × 100%0 O- Y! p. \。 F) P/ `/ O/ S8 f+ H7 E

Guanjiao

The angle between the coronal plane and the waist horizontal plane. 7 o/ k: Y% y' F4 g

Bottom tip (or bottom facet) of the base

The intersection of the main facets of the pavilion is a dot or small octagonal facet. ，m" X. }/ h( W

Ratio of bottom to top

The percentage of the bottom tip diameter relative to the average diameter is calculated as follows.

Bottom tip ratio = bottom tip diameter/average diameter × 100%

Cutting classification

Through measurement and observation, the perfection degree of diamond processing technology is graded from two aspects: ratio and modification. 1 f u) r，a( H4 e: V！ F# e

Cutting method

The cutting method is different from the shape of a diamond. Simply put, there are three cutting methods: step cutting, bright cutting and mixed cutting.

Cushion cut diamond long angle step cut /X- `! `/ i* K/ I+ k

Cut too deep

Cutting refers to the angle at which the technician cuts the cutting surface and the proportion of each part of the diamond after cutting. If the proportion of diamonds below the waist is too deep, the light will flow away from the bottom or side and lose its luster. The value of diamonds has also become lower. 4z & amp； V7 [8 f+ p3 outer diameter

Diamond) i( G/ B+ s: B- Z/ f7 n

It is an equiaxed (cubic) natural mineral, mainly composed of carbon. Mohs hardness 10, density 3.52 (0.0 1) g/cm3, refractive index 2.4 17 and dispersion 0.044.

Diamond grading

Diamonds are classified from four aspects: color, clarity, cut and quality (carat), which is called 4C classification for short. 7 n，k！ U3 q) L: s4 R

The diamond master sets the color stone. q r，U6 7 t！ d； b9 '

A set of standard cut diamond samples with calibrated color grades, representing continuous color grades from high to low in turn.

Diamond lamp colorimetric lamp

Fluorescent lamp with color temperature in the range of 5500 k ~ 7200 k

Diameter 0. b) n * V9X3K5D3 t

The diameter of the circular horizontal plane at the waist of the diamond, where the maximum value is called the minimum diameter, and the value of 1/2 (maximum diameter+minimum diameter) is called the average diameter.

Dispersion dispersion +} $ q (q'm: v,]: x&; y

The light entering the diamond is internally reflected at different tangent angles, and the distributed reflection of the light produces seven colors of the rainbow, which is called dispersion.

Extra surface

All redundant aspects except the specified aspect.

Emerald-cut diamonds Emerald

Faceted part+n-]&t&; I+_ (}

After the diamond embryo is polished, the smooth and delicate surface forms the shape of a diamond. The reflection of light from these facets makes the diamond shine. :Q B9 R % B& amp； a4 E# t！ B

Colored diamond, colored diamond

Diamonds of other colors, such as yellow, pink, blue, green, red and black, are ever-changing, but they are extremely rare and of high value. 0 L6。 o-U & amp； F0 A% ]% N' R

Fancy cutting

Any form of diamond cutting except circular. Shaped cutting includes long and narrow squares, emeralds, triangles, pears, princesses, ellipses and water drops. (]' L6 P( R) ]$ ]- {！ F8 de fu

Feather feather * O- N+ S+ \( ~

The part inside or extending into a diamond. 8 a- T2 L* D) ~。 ~5 @

Dressing/polishing 3J0N3}-I (n&; b！ P2 D "？

Surface smoothness of diamond after cutting and polishing. If the polisher is excellent, the diamond will be polished with high quality. 8 i* e！ q9 b $ E5 |(^)v-o

Flame chromaticity

Refers to the intensity of color chromatographic light reflected by diamond decomposition. It is closely related to tangent ratio and symmetry.

Flat-topped inlay

The flat-topped inlay is similar to the gypsy inlay, but the top of the ring arm is thicker, the main stone is inlaid in the center of the top, and the diamond waist is fixed with a metal plate.

Perfect FL level

Experienced raters observe with a magnifying glass of 30 times under the standard light source, and define without finding any defect features. In other words, the diamond does not contain any defect features larger than 5 microns and has sufficient brightness. 6z； M: z) d6 s6 y，j0 Q+ ` 1 L！ r

fluorescence intensity

The intensity of visible light emitted by diamonds under the irradiation of long-wavelength violet light. Some diamonds will emit white, yellow or blue light under ultraviolet irradiation, which is called fluorescence effect. Ordinary non-professionals generally don't notice. Fluorescence effect is not an index to measure the quality of diamonds, but a characteristic of diamonds. And personal preferences for this are different. China is divided into four grades according to the luminous intensity of diamonds under long-wave ultraviolet light: strong, medium, weak and none. Foreign countries are usually divided into six grades: negligible, none, inert, dim, blue and strong blue. (r8 p & ampZ3 P$ D4 H, USA)

GIA American jewelry association

Gemo Logical Institute, American Jewelry Institute, is an international authoritative diamond testing institution. +F(b " t %[； l . s； g: Z k

Waist: k '` 0z9e (X6); ~

The circumference with the largest diameter in a diamond. ! V”V U:j； v

Waist seal tassel waist crack% K, b*? 5 Q% e，v( W5 n2 s

During the grinding process, tiny cracks may appear on the diamond waist. Slight cracks can be completely removed after re-grinding.

Waist circumference/waist circumference ratio

The percentage of waist thickness relative to the average diameter is calculated as follows

Waist thickness ratio = waist thickness/average diameter × 100%

Growth or texture line diamond texture 6 f! X5o8 * North/North & I love you.

These thin lines or planes are internal defects and can only be detected by rotating the diamond at a very low speed. They appear at a certain angle and then disappear in an instant.

Gypsy set gypsy mosaic 7cu&; d2 z: w" \3 "

This is a common way of setting men's diamond rings. The top of the ring arm is thick, and the main stone is embedded in the center of the dome. The design without metal claws makes the ring lines more concise and smooth. " @，Y9 B) m' ]

Red arrow cuts eight arrows and eight center cuts.

Round drill shape, with eight arrows on the top and eight centers on the bottom. The cutting loss of standard blank with eight arrows and eight centers is large.

Heart-shaped diamond-shaped heart-shaped 9 R R( H+ p( m

HRD (Belgian Diamond High Council):

Belgian Diamond High Council, an international authoritative diamond organization and testing organization. The highest official management body of the Belgian diamond industry. HRD is the spokesman of four diamond exchanges in Antwerp, Belgian Federation of Diamond Exchanges, relevant trade organizations and trade unions. The purpose of HRD is to develop and protect the diamond trade and industry in Belgium. The organizational structure of HRD is the General Assembly, Board of Directors, Council, General Management Office, Diamond Bureau, Gemological Institute, Diamond Science and Technology Research Center and Certificate Department. 6 S) V# Y) h- ` 1 I

IGL 1 `: v: [+ W3 u6 b4 R6 y

Independent Gem Laboratory Company is the authoritative diamond testing organization in the United States. . E2 Y) v 1 i/ j2 n% n

Illusion mosaic

This mosaic method is more interesting than others, because the metal next to the main stone is carefully designed to make the main stone look bigger and more charming.

Conclusion contains+h0y; w( w3 d+ Y

Because it is naturally formed, every diamond has different flaws inside, so every diamond is different. You can know the number, size and types of these natural birthmarks from the clarity grading rules. Inclusions can be divided into cloud, crystal, needle and feather. The position of inclusions also directly affects the clarity and value of diamonds. 4 Z5 T $ J； Y# y8 e# G- {。 Ask and answer. y0 Q

Sawtooth natural concave original picture

The clean surface of a diamond is concave, just like the natural clean surface inside a diamond.

Internal defect-free IF stage

The experienced grader observed the diamond under the standard light source with a magnifying glass of 30 times, and found no defects in the diamond. . m# } 1 ]" O9 C

Junction crystal plane:

Retain the natural crystal surface at or near the waist of the diamond to maintain the best quality. v 1 i* X" q) N0 _ x

Laser drilling laser marking

Traces left by lasers and chemicals when removing black inclusions from the diamond. Tubular or funnel-shaped marks are called laser holes. Can be filled with high refractive index glass.

LC class "|# f R) E6 M: T

Experienced raters observe with a magnifying glass of 10 times under the standard light source, and define without finding any defect features. In other words, the diamond does not contain any defect features larger than 5 microns and has sufficient brightness. (highest definition in China standard). The following situations still belong to LC level:

The extra facets are located in the pavilion and the crown is not visible.

The primary crystal plane is located at the waist line, which does not affect 4p U(e & amp； o+ |！ J 1 z

3. There are very slight features inside and outside the diamond, which can be removed after slight polishing: V 'o4t% i+LE3A # q) B # o.

Lower waist edge smooth surface &? C $ J S & ampD+ a

A triangular facet between the waist and the main facet of the pavilion. 1 P(m 1 { ' {； D6 Dee

Master of fluorescence intensity contrast sample

A set of standard circular cut diamond samples, with calibrated fluorescence intensity grades, consists of three pieces, which represent the lower limits of strong, medium and weak grades in turn. {5 t' |！ A4 J4 Y% e！ f

Blue-pointed cut diamond

Mixed cutting mixed cutting "u% z% v n &；; Z* G7 g- g" x

This cutting method includes both step cutting and open cutting. Mixed cutting gives diamonds both the beauty of beryl and the light of bright cutting. -d; D) C' I7 and S" l v/ a' _

Mohs hardness

Internationally recognized hardness tester. % l6 [: p* l3 W$ I- p5 A M0 M

Natural surface texture! h # f； [! }# q5 m 1 K9 ^.r

Natural growth marks on the surface of diamonds.

Waist of needle: z, \+ b- }+ ~+ @: D' T6 d5 [" `* T].

A part of the waist of a diamond, where tiny needle-like cracks go deep into the interior.

Nickel 30f &；; E2 K C ` & ampe

Often used to add to k platinum.

NGTC (National Jewelry and Jade Quality Supervision and Inspection Center) (w% M: d6. T

The National Gemstone Testing Center is a national professional quality inspection institution authorized by the relevant state departments according to law, and it is the authoritative institution for jewelry and jade testing in China. The inspection center provides entrusted inspection services to the society, undertakes national market supervision and inspection, arbitration inspection, import and export commodity inspection, and formulates and revises relevant national standards. The main reviser of national diamond standard. |8 z2 G+ y，d！ S

Oval cut diamond oval/h; j" j4 _ 1 i. |" }

Poor p-level

Experienced graders can easily find defects with the naked eye, thus affecting the "temperature" of diamonds. 8h $ v . Z % H； n； w； s； ~# U0 i

Pavilion department

There are 24 or 25 facets above the waist. * V(Q ' {/j . | % S； k

Main surface of pavilion

Pavilion quadrangular facet. $ F( j/ E# i8 x

pavolion angle pavilion corner 5d-E * E # N # z

The angle between the main surface of the pavilion and the horizontal plane of the waist. )R7 R3 O，X' ]2 Z8 {6 t

The proposed ratio of the pavilion is * N$ J5 J+ P( i7 q/ J 1 Y/?

The percentage of the pavilion depth relative to the average diameter is calculated as follows.

Pavilion depth ratio = pavilion depth/average diameter × 100%

Mosaic/c (l&; ? / g" P/ W+ O \

Small diamond inlay technology, diamonds are closely inlaid, so there is no metal. The inlaid surface looks all paved with diamonds. & ampQ4 y9 v " X2 E2 \ Q4 R-y & amp； m% N

Ash ash

Wax cavity mold is a jewelry making process.

Pear diamond pear-shaped

Needle tip inclusion

Tiny natural inclusions in diamonds. ，j 1 q e； h/ X

Platinum platinum, j8 W9 l! x/K 1 j9k:Q3 V ' l . U； q

The ideal metal for setting diamonds, platinum is its symbol.

Score (q `# g I' B/B # x. |

Diamonds weighing less than 1 carat are usually counted in minutes, 1 carat = 100 cents.

Polishing grinding/polishing

Refers to the process in which a cutting technician polishes a diamond embryo and makes a diamond section. The polishing degree of diamond surface is an important index to measure the quality of diamond.

Poor cutting; Q: #. U

Cutting refers to the angle at which the technician cuts the valve surface and the proportion of each part of the diamond after cutting. Cutting too deep or too shallow is called bad cutting. When the proportion of the diamond below the waist is too deep or too shallow, the light will flow away from the bottom or side and lose its luster, and the value of the diamond will become lower. 8 e6 L: {( n？ 4 i( f# s5 L

Princess cut diamond square improved bright cut diamond "S z" T) \# T

7 \! c ' m # O & amp}

Pointed inlay/Tiffany inlay Pointed inlay

A four-claw or six-claw inlay that holds a gem with slender claws. This kind of inlay shows the beauty of diamonds, which is convenient for observing the lathe work, color and clarity of diamonds. It was invented by Tiffany, a famous jeweler in new york, and is now widely used. -a $ S " E & amp； _, p4 _% |7 7V

Proportion: }7 h8 n7 h* _4 O

The percentage of the value of each face of a diamond relative to the average diameter. & ampy，e ' J； U* Q9 r9 |) ~' W

Radiation cut diamond turns red and bright cut) e8e；; . Information technology development department, health and wellness department. {0 w

Ring size comes first.

The size of the ring finger ring is called the hand inch, which is expressed by numbers. The size of oriental hand is between 8 and 24.

Rose gold rose gold * i0 t' E L: C6 F' ~2 T6 F

A yellow alloy containing 75% gold.

Circular cutting circular drilling tool

Ideal cutting, also known as Torkovsky cutting. It was the Polish mathematician Marcel Tolstovsky (1899 ~ 199 1) who first calculated the cutting equation that theoretically maximized the reflected light of diamonds in 19 19. The width of the platform should be 53% of the total width, and the angles of the pavilion should be 40 degrees and 45 degrees. There are 57 or 58 faces.

Rhodium rhodium

A platinum group metal.

Circular diamond-shaped circle

E* ]5 o- O5 m 1 V6 Z

Shallow incision The incision is too shallow.

Cutting refers to the angle at which the technician cuts the valve surface and the proportion of each part of the diamond after cutting. If the proportion of diamonds below the waist is too shallow, the light will flow away from the bottom or side and lose its luster. The value of diamonds has also become lower. 9 B ' `； R) x* D5 ]) B# n( E5 L

Shape shape

Refers to the type of diamond, such as circle, triangle, square, olive point, pear, oval or heart.

Step cutting

1 m9 Q 1 Y first-class cutting surface such as stairs. Beryl and long step cutting are examples of step cutting.

Star face, star face! S3 B# @( i( e 1 h7 Y/ V

A triangular facet between the main facet of the crown and the desktop. * D- F2 R 1 W# X！ w！ ~.g( Z

Slightly contains silicon level.

Experienced classifiers can easily find small defect features with a magnifying glass of 10 times. According to the size, location and number of defect features, it is decided whether it is SI 1 (a few visible inclusions) or SI2 (some visible inclusions). * h2 N9 I、D、s7 L

Twinkle 2 P( K" _ g: q* y)

When a diamond reflects light, the weak light emitted by the cutting surface is called flash.

Yinyin

Often used to add to k platinum. + Y7 o4 i/ M" R" i$ O6 v

Single mosaic

The setting of a single gem.

Symmetry, symmetry, 6m9p6k (z&; A 1 ^7 Y

The horizontal symmetry of each part around the center point after diamond cutting and polishing, that is, the arrangement of cutting plane and its angle. Like ratio, it is also an important index to evaluate cutting. If the lathe work and proportion of a diamond are excellent, symmetrical cutting will make the flash and flame more intense. The evaluation of symmetry in foreign certificates is more detailed, and the order from high to low is ideal (ID), excellent (EX) (or premium), very good (VG), average (F) and poor (P). $ k:U7 C & amp； @0 z 1 P9 v* d

Table table, Z! c，@5 L* f+ C5 G，Y3 x

Octagonal facets of the crown. 3o/_ & amp； q/ A3 s' e+ z

Table proportion

See 8 n/ Y8 o0 W0 h- G. l7 i9 F5 G below for the formula for calculating the percentage of mesa width relative to average diameter! K

Table width ratio = table width/average diameter × 100%

The tension setting wall is inlaid with 5W5t (L&; O5 X3 R，o”^

Under the pressure of the metal arms on both sides, the main stone was urgently fixed. :T2 i- O8 {+ { K

Full tooth height

Vertical distance between diamond table top and bottom tip.

The total depth ratio is 2 H, K" Z9 y/ r3 j.

The percentage of the total depth relative to the average diameter is calculated as follows &; n！ {; @! m5 [8 |/ u0 F: L！ abstruse

Full depth ratio = full depth/average diameter × 100%

T.w. (total weight) "r7 K2 r8 b, P7C; M0 meter

The total number of carats of diamonds set in jewelry. & ampV { 5 l/P4 D(F & amp； r

Tapered long stick pointed step

A diamond with a stepped cutting surface gradually narrows on the longer side. * f4 | 1 f9 ~ U5 r

Trillion triangle

A triangular diamond with 50 facets, usually used as a foil stone.

Twin strand polishing pattern

Small linear marks caused by improper polishing of diamonds are parallel to each other at the same moment.

Upper main facet Crown main facet (kite face)

Crown quadrilateral facet.

On the main surface and waist! ~ & ampe # w； F( Y 1 B 1 X，a； j

A triangular surface between the waist and the crown. :|/} % T+I7 Q； ordinary

Very, very slightly including the level of vv.

Experienced classifiers can find tiny flaw features with a magnifying glass of 30x. It is extremely difficult. According to the size, location and number of defect features, it is decided whether it is VVS1(less inclusions at 30x) or VVS 2 (more inclusions at 30x).

Very slightly including the level% T2 J* W t) U3 I6 ~% t6 h.

Experienced graders can find small defect features with a magnifying glass of 10 times. The difficulty is not too difficult. According to the size, location and number of defect features, it is decided whether VS1(less inclusions at10x) or VS2 (more inclusions at10x).

White background shadow guide 6L3 y&: r) t! l)m-_； p

Whiteboard or white paper used as a colorimetric background has no obvious directional reflection. 9 _ $ _ 6 { 6j/h & amp； n/ x. d( @

Platinum platinum 3 |: `% z 1 C. a4 C( G" u0 B)

A white alloy containing 75% gold.