Accurate identification of the color of Hetian jade is very important. It is best to identify Hetian jade in natural light, because under different light sources, Hetian jade skin color will show different states, avoiding observation under sunlight or colored light. How to identify Hetian jade under the light source?
How to identify Hetian jade under the light source?
The ancients said that "there is no jade under the lamp":
Nephrite has different shades when viewed under different light sources, and different colors of nephrite perform differently under the same light. It is best to use natural light when distinguishing the classification. In case of strong sunlight, avoid direct sunlight. The auxiliary light source is an ordinary fluorescent lamp with a color temperature of 5000-7000K.
The environment has a negligible effect on color.
The laboratory should use neutral white and gray as the ambient color, and the samples to be compared and compared should be placed on large white cloth, cloth paper or white paper for identification colorimetry. The backing material requires weak fluorescence and is flat and resistant to dirt. It is also not necessary to have strong reflections. Different workbenches in the same laboratory must be fixed to the same backing for a long time as a colorimetric background.
Sample thickness factor:
The thin sample will appear lighter in color and the thicker sample will look darker. Therefore, the general laboratory specifies that the colorimetric part is between 5 and 8 mm thick. Insufficient or excessive parts should be technically measured to determine the depth of the color.
According to practical experience, two or three of the three shades of light blue, gray, and yellow should be selected to establish a colorimetric standard sample to ensure the stability of the white jade/white jade color base. Establish a boundary line between topaz and blue and white jade to ensure the stability of the classification of topaz. Other color categories should be referenced to the sample library so that staff can often compare references in actual work.
Identification of colors:
It should be operated by inspectors who have been trained in the system and experienced, and inspectors should be familiar with and understand the industry tradition. It is difficult for untrained personnel to identify small differences in color, nor to take into account some of the precautions and industry traditions of identifying classifications, which can cause large errors in approaching classification boundaries and concepts.
In addition, when performing color comparison, it is necessary to pay attention to the sensitivity of different people's eyes to gray, yellow, light blue and other hue. The comparison test shows that different people have color parallax, color blindness and color weakness. Note that the natural light color temperature is different at different times in the morning, noon and afternoon. Pay attention to the difference of the position, front and back, and direction of the sample. Pay attention to the effect of sample transparency on color, pay attention to the effect of color on the sample on the color, sugar, and other colors.
Knitted Scarf For Child,Custom Logo Knitted Scarf,Custom Knitted Scarf For Kids,Knitted Scarf For Children
Huaian Changfeng Knitting Co., Ltd. , https://www.cf-knitting.com