Gemstones

Gemstones and Semi-Gemstones

Gemstones:

Gemstones, a mineral, a precious or semi-precious stones that may useas a jewelwhenitscut and polished.

Gemstone color can be described of hue, situation and tone. Hue is commonly known as the “Color” of the gemstone. Situation refers to vivid and brightness the hue (color). And, tone expresses the lightness to darkness of the hue.

Getting a gemstone certificate and laboratory report is the best way to receive all the information on quality, origin and treatment. The geo lab use high-tech equipment to identify and descript a gemstone in details.  The most well respected gemological laboratories are:

GIA: Gemological Institute of America.

AGS: American Gem Society

GGL: Gubelin Gem Lab

SSEF: Swiss GemologicalInstitute

GRS: Gem Research Swiss Lab

 

Ruby:

Ruby is a pink to blood-red colored gemstone wichtige quelle. The color of a ruby is due to the element of chromium.

The quality of a ruby is determined by its color, cut, clarity and cut as well as carat weight; they all affect its value. Color of “Blood-Red” or call “Pigeon Blood” is most valuable. Clarity of a ruby is similar of a diamond, rutile inclusion is needle-like, without it, a ruby may indicated has been treated.

A premium quality ruby should carry a gemstone certificate, graded as 4C’s: Carat, Cut (Shape), Color; Clarity, Dimension and Identification, in which report its natural or treated.

Rubies are also evaluated on the basis of their geographic origin.

 

Sapphire:

Sapphire is a precious gemstone. It has remarkable hardness of 9 on Mohs scale. Typically color of sapphire is blue, but natural fancy sapphires have color in yellow, orange, purple, green and colorless.

The cost of natural sapphire varies depend on their color, clarity, cut, size (carat weight) and overall quality.  Blue sapphire is valuated based upon the purity of their primary hue.  Premium quality of sapphire often carried with respected gemological laboratory report.

 

Emerald:

Emeralds are green precious gemstone, its colored in green. And, most emerald s is highly included, so their toughness (resistance to breakage) is poor.

Emeralds, like other gemstone, are graded with 4C’s: Color, Clarity, Cut and Carat Weight.

Grading an emerald, the color is the most important criterion by far, and, the clarity is come to second of an emerald grading. Beside all above, a high degreed of transparency of an emerald can be considered as a top stone. There are plenty of commercial grade emeralds around but fine and extra fine emeralds are extremely rare.

The color (hue) of emeralds is ranging from yellow-green to blue-green with primarily being green. A fine emerald should have a vivid (bright) hue.

Emeralds have tended to be numerous inclusions and breaking fissures on its surface compare with other colored gemstones. Unlike other gemstones, the clarity of an emerald is graded by necked-eyes, if an emerald has no visible inclusion to the naked-eye, it will be considered as Flawless.

Lacks of surface breaking fissures are extremely rear for emeralds, therefore treatment of emerald are common, most of emerald are treated with “oil” to enhance its clarity and transparency.

 

Tanzanite:

Tanzaniteis named by Tiffany Co. Tanzanite has very short history of being a gemstone; it has been, only, discovered in Tanzania in 1967. Tanzanite is only found in a small mining area of Tanzania.

Tanzanite is violet variety of the mineral zoisite belong to the epidote ground.  Tanzanite, most of them, is deep blue with some purplish tone. Tanzanite has aunique phenomenon, its can appear differently in color when viewed under alternate lighting conditions and directions.

 

Semi-Gemstones:

A semi-precious gemstone is still classified as Gemstones. It’s a portion of a mineral, in refined and cut form, used to create jewelries and other embellishments.

“Precious-Gemstone” versus “Semi-Gemstone” is a commercial term for the marketing purpose. In term of Precious Gemstones are Diamonds, Rubies, Sapphires, Emeralds and sometimes Tanzanite is within.  All other gemstones are classified as Semi-Precious stone.