Introduction: Color change garnets are a variety in the garnet family within the pyropespessartine solid solution series.
Colors: wide variability in color changes from incandescent to daylight; some of the color changes often seen are purple to bluegreen, pink to yellow or brown, brown to green.
Clarity: Color change garnets are of clarity Type II. Gems in this type typically grow with some minor inclusions in nature that may be eye visible but usually are well hidden or require magnification. Identifiable inclusions include rutile, pyrite and apatite crystals.
Stone Sizes: Typically sizes don’t exceed 5 ct
Localities: Tanzania, Kenya
Treatments: None
Gemology:
-Refractive Index: 1.760 (-0.020,-0.18)
-Birefringence: None (singly refractive)
-Optic Character: Singly refractive (sometimes shows anomalous double refraction (ADR))
-Specific Gravity: 3.78 to 3.85
-Hardness: 7-7.5
Toughness: Fair to good
-Chemical Composition: (Mg,Mn)3Al2(SiO4)3
-Cause of color: chromium, vanadium
-Absorption Spectra: strong lines at 4100, 4200, 4300 (occasionally merging to form a single wide band below 4350); also shows a combination of other lines at 4600, 4800, 5040, 5200 and 5730 and abroad
band centered around 5700
-Fluorescence: None
-Cleavage: None
-Phenomena: Color change from incandescent to daylight
Name: Color change simply refers to the wide variety of colors seen in different types of lighting.
Dates: All species of garnets can be used as the birthstone for January. Garnets are also the gem of choice for second anniversaries.
Care: Ultrasonics are usually safe but risky with liquid inclusions. Steam cleaners should never be used. The safest method for cleaning is with warm soapy water. Abrupt temperature changes will likely cause fracturing.
To see available color change garnets, click here.