Malaian oranssi granaatti sydän kuvallisella aitoustodistuksella
Spessartiini granaatti kuvallisella aitoustodistuksella
Alkuperä (todennäköinen) : Tansania
Paino ( ct noin ) : 1,2
Mitat ( mm noin ) : 7,2 x 6 x 3,8
Hionta : viistehiottu sydän
Puhtaus : VVS
Erinomainen Erittäin hyvä Hyvä ”kakkosluokkaa”
Ominaista : loistava sydän hiontainen Malaia granaatti, keltaisen oranssi,
Malaia is name given to garnets orange to pinkish orange to red in color which do not match the color and gemological properties of any of the other more well known varieties of garnet. (Some authors spell it Malaya). Indeed, the word malaia means out of the family in Swahili. Primarily composed of spessartine and pyrope, the color and gemological properties occur in a range which can overlap with grossularite, rhodolite, and pyrope. Some of them may change color under daylight and incandescent lighting probably possibly due to the presence of vanadium or chromium in trace amounts.
|Color Key:||orangey pink, champagne, orange brown, copper-pink.|
|Refractive Index:||1.73 - 1.81|
|Chemical Composition:||[Mg3 + Mn3]AL2(SIO4)|
|Hardness:||7 - 7.5|
|Density:||3.65 - 4.20|
|Ocurrence:||Kenya, Tanzania, Madagascar|
It’s the color that sets these stones apart. That illusive orangey pink color… highly prized and sought after in padaparadscha sapphires and imperial topazes but rarely available in the world of gemstones.
The only commercial deposits of Malaya occur in the Umba Valley in Kenya, in Northern Tanzania and in South Madagascar near Bekily. Large sizes are uncommon and most of the rough is small.
Malaia garnet can be difficult to separate from grossular hessonites because the two varieties can be identical in color and can also overlap in both density and refractive index. Specific identification of Malaya (pyrope-spessartine garnets) normally requires chemical analysis. Malaia garnets contain Mn, and Mg, with traces of Ca while grossular hessonites do not contain Mn, or Mg and contain more Ca. A spectroscope is the easiest way to separate the two varieties. The absorption features are due mostly to Mn2+ and Fe2+. Assignmnent of the bands at 503, 610 and 687nm to Fe2+ and at 483 nm to Mn2+ is consistent with data from other literature. Additional bands at 459 and 525nm can be assigned to both Fe+2 and Mn2+. Additionally, an intense band between 410-430 can signify of the presence of Mn2+ or Fe2+. Well equipped labs can also use an FTIR (Fourier Infared Spectrometer) and EDXRF (Energy Dispersive X-Ray Fluorescence Spectroscopy) to determine the chemistry.