Black white and brown refer to tones and saturation not hues. Historically all gemstones were graded using the naked eye. The basic hues are red orange yellow green blue violet and purple. Type 1 gemstones are usually found almost completely inclusion free within the market. Description industry standards agta codes.
However the grading is not limited only to these qualities and other factors such as value for money popularity and even feedback from customers are taken into account while grading gemstones. Gia tests every material submitted to determine whether it is natural or not and discloses any treatments discovered during our examination. An evaluation of a gemstone s symmetry proportion and appeal while viewing the stone with its table facing the viewer. A gem s tone refers to a gem s relative lightness or darkness. Gia is the world s most trusted name in diamond grading and gem identification.
Clarity is one of the four cs of gemstone grading. Hue and color saturation. An assessment of a gemstone s proportion balance and uniformity determined by a number of criteria including length to width ratio bilateral mirror images etc. Grading the quality of gemstones. Of course other factors can impact a gem s appearance and structure most notably the cut.
RELATED ARTICLE :
The introduction of 10x magnification as the standard for grading clarity. With objectivity and expertise as its hallmarks gia ensures the integrity and accuracy of every report it issues. Diamonds are graded by whom using a system developed by the gemological institute of america gia in the early 1950s. We are an independent gem testing and jewellery appraisal laboratory in singapore. The inclusions on high quality type 1 colored gemstones are so tiny that they can only be detected under a 10x magnification.Light green to greenish blue included weak to low color change. Gem varieties for grading type 1. It is recommended that when purchasing a type 1 colored gemstone the buyer should expect the gem to be almost loupe clean. Green to greenish blue slightly included moderate to medium color change. A member of the singapore jewellers association we specialize in diamond grading gemstone identification and jadeite jade identification.
Gemstones have no universally accepted grading system. A gemstone s clarity grade indicates the relative absence of inclusions materials trapped inside the gem fractures and blemishes surface imperfections that affect its appearance and structural integrity. Black and white are tones from darkest to lightest. With our experienced gemologists we offer you services with integrity reliability and consistency and enjoyable experience learning all about gemstones. A gem s saturation refers to the intensity of its hue.
Alpha grading is a commonly heard term in conjunction to grading of gemstones this grading is based on several qualities such as colour cut and clarity. Alpha grading is a commonly heard term in conjunction to grading of gemstones this grading is based on several qualities such as colour cut and clarity. Gemstones have no universally accepted grading system. Light green to greenish blue included weak to low color change. The introduction of 10x magnification as the standard for grading clarity.
RELATED ARTICLE :
A gem s saturation refers to the intensity of its hue. Clarity is one of the four cs of gemstone grading. However the grading is not limited only to these qualities and other factors such as value for money popularity and even feedback from customers are taken into account while grading gemstones. Black white and brown refer to tones and saturation not hues.
