Clarity
The hue of the gemstone must be constant throughout. Zones of various colors reduce the gem's quality and, thus, its worth. For instance, sapphires have a good amount of zoning.
Although color zoning should not be seen from the crown and is less significant from the pavilion side. Generally speaking, the lack of inclusions makes a gemstone more attractive and increases its value, but in other circumstances, they can aid in determining whether a gemstone is natural or man-made or play a key role in determining its place of origin.
Diamond clarity has been categorized in a very specific way by gemological institutions that is universally recognized. Using a 10 X magnification, diamond grading is done.
Colored gemstones present a unique set of challenges since they come in a variety of mineralogical species, making it more challenging to develop a clear strategy.
The harmful impact of imperfections on light transmission, and consequently on the gemstone's beauty and brightness, is taken into account when evaluating a gemstone's clarity.
GRADE | APPEARANCE TO THE UNAIDED EYE |
EC (Eye-clean) | The stone appears clean to the unaided eye |
SI (Slightly Included) | Type I Minute inclusions difficult to see to the unaided eye Type II Minor inclusions somewhat easy to see with unaided eye Type III Noticeable inclusions apparent to the unaided eye |
MI (Moderatedly Included) | Type I Minor inclusions somewhat easy to see with unaided eye Type II Noticeable inclusions apparent to the unaided eye Type III Obvious inclusions very apparent to the unaided eye |
HI (Heavily Included) | Inclusions are prominent with a negative effect on the appearance |
Colored gemstones are divided into three groups with different clarity standards:
Type I: gemstones are typically transparent and have no obvious inclusions to the unaided eye. tanzanite, pink and yellow beryl, green tourmaline, blue zircon, and aquamarine are all included.
Type II: gemstones are those that frequently include inclusions, yet these do not detract from their beauty. includes all tourmalines, peridot, garnet, iolite, spinel, quartz, zircon, and corundum (but not ruby) (except green tourmalines).
Type III: always include inclusions as a result of their origin, including emerald, ruby, and red beryl.
Transparency
The degree of light that can pass through a gemstone determines how transparent it is. Since inclusions within the stone may block or divert the passage of light, transparency and clarity are related.
Transparency is described using the following terms:
transparent: objects viewed beyond the gemstone appear sharp.
semi-transparent: images appear slightly distorted and blurry.
translucent: the objects are hardly visible, and images are distorted, light is still transmitted over the gemstone.
semi-translucent: only a small part of the light is transmitted over the gemstone.
opaque: light doesn’t pass through.