Red, sapphire, value and its particle size, weight has the close relation, the following half carat gem is relatively common, inexpensive; If more than one carat is much more expensive, 3 carat above will be geometric series rise. If more than 10 carat, and the quality and is very good, is very rare, value can reach millions of dollars.

Red, sapphire, generally can be divided into the following several level to estimate value: 0.5 carat the following, fine grained, very easy to get, used for group set very cheap; 0.5 1 carat, small grain, easy to get, can be used as small ring surface, cheap; 1-2 carat, medium grained, general can afford to buy, can be used as ring surface pendant; 2-3 carat, larger grain, value higher, the market demand, 3-5 carat, big grain, high value, rare; More than 5 carats, a large grain, value expensive, very few and far between.

Cut is also affect the value of the important factors. Red, sapphire in cut very exquisite, including facet and element face two major categories; The shape has oval, round, emerald shape, pear-shaped, olives type and mixed type, etc. One of the most popular is a hybrid form, namely wide oval. Cut of the evaluation is not like diamond that strict, generally do not take a gem value of the great component, but if cut too poor, is greatly affected the value of it.

Good cut pay attention to three points: 1. Cut positioning: because red, sapphire is anisotropic, have polychromasia. Cutting should make mesa strictly perpendicular to the long axis direction, avoid pleochroism influence, make finished products from mesa can see the pure, saturated color, this is the correct orientation. It could lead to color deviation, under the influence of pleochroism, with noise. 2. Proportion and symmetry: no matter use which kinds of precious stones cut type, must conform to the standard requirements, and better symmetry, cannot skew. The length, width and thickness of proportion and Angle is very important, must conform to the standard, because these standards is based on precious stones and refractive index of total reflection principle and design, can achieve the best effect. If cut thin will light leak, color shallow, dispersion effect is poor, use jargon said is not "rotor", call it "fisheye effect", appear inflexible without luster, cut too thick will make the color becomes dark, also influence "rotor". 3. Polishing degree: polishing quality will affect the luster of the gem. High quality polishing make stone revealed more luster, shining. 4. Starlight effect: containing three groups of directional arrangement of fibrous inclusion red, sapphire, using arc grain surface cutting can produce star effect. This kind of precious stones cut not only consider the symmetry and proportion, must choose the right direction and position, make the finished product starlight is highest, if the cut is bad, deflection value will be reduced.
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