Everything About Color Change Gems


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Why Are Alexandrites So Unique?
Alexandrite was first discovered in 1830 in a Russian emerald mine in the Urals. On the occasion of Prince Alexander II's 21st birthday, the gem was dedicated to him by the mine's workers.

Alexandrite contains a trace of chromium, making it the most effective at transmitting green light, second best at transmitting red light, and very effective at absorbing all other wavelengths. As a result, the stone transmits the most green light during the day, when it is exposed to sunlight, giving it a green appearance. It also appears blue when illuminated by an approximately white light, comparable to daylight. However, when candles, oil lamps, or tungsten filament incandescent lamps with a high red content are used at night, the stone transmits the most red light, giving it the appearance of being red. Alexandrite is an excellent treasure due to its striking and obvious color-change.

The alexandrites and garnets in this collection exhibit a moderate to strong degree of color change. Additionally, if required, we have some color-change sapphires. Let us know in DM and watch our different stories for more information!

Crystallography Of Alexandrite
Alexandrite crystallizes as an orthorhombic structure with the Pnma space group (Z = 4 form units per cell). The parameters of its conventional mesh are as follows: a displaystyle an a = 9.408, b displaystyle b b = 5.479, and c displaystyle c c = 4.429 (volume of the mesh V = 228,293); the density calculated is 3.7 gcm-3.

Alexandrite, like chrysoberyl, has an olivine crystal structure, with Be2 + cations occupying the tetrahedral sites and Al3 + cations occupying the octahedral sites. Oxygen is arranged in a compact hexagonal stack. Be-O has an average bond length of 1.638 and Al-O has an average bond length of 1.914.
Set Brazilian Alexandrite 2.44 cts

Weight (cts): 2.44 cts
Origin: Brazil
Shape & Cut: Oval
Single/pair: Set
Stone type: Alexandrite
Color: Color Change Greenish-blue to Violetish-pink
Certified: SSEF

For more details, click here

Where To Find Garnets?
Only four places in The world are home to the garnet color change: Tanzania, Kenya, Madagascar, and Sri Lanka. The weak Tunduru deposits in Tanzania's Ruvuma region confer a lovely beige / pink-orange hue to green / red. Other Garnets of comparable quality are found in Kenya's Taita-Tavita region and the Umba Valley in the Tanga region.

The most exquisite specimens in Sri Lanka are found in Wellawaya and Embilipitiya. In Madagascar, a small deposit in Bekily produced magnificent Garnets that were unusually blue to blue-green in daylight due to their surprisingly high vanadium content, and red to purple when illuminated by an incandescent lamp. These are extremely desirable and highly valued on the global market.
Color-change garnet is a combination of pyrope and spessartite garnet that changes color under natural and artificial light. This phenomenon is extremely rare and highly sought after by collectors. Color-change garnet appears dull and muddy in mixed lighting; however, in proper lighting, it reveals its true colors.
Color-change effect
Pleochroism Vs. Color Change
Garnet changes color in response to the type of light source, which is a completely different phenomenon than pleochroism, which allows for the observation of different colors in a gem depending on the angle of observation. When Garnets change color, the intensity of the phenomenon can be quite spectacular, far exceeding the change seen in the majority of Alexandrites (which remains, moreover, the stone with the most color change. known and most coveted).

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Benjamin Poudevigne
Social Media Manager at GemMatrix
With over ten years of marketing experience, I finally decided to settle down in Bangkok to work in an area that I have always been interested in: the gemstones industry. I'm still learning how the market works on a daily basis, and I enjoy sharing my experience with those who are interested in learning more about gems in general.