Global Gemology - Rare Gems & Jewels
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GARNET

Picture
Marquise pyrope almandine garnet set diagonally in this vintage 14K gold designer ring, by Clyde Duneiere
Diagonally set marquise garnet ring
Group:  Garnet
Mohs Hardness:  6.5 to 7.5 out of 10
Color:  Nearly all colors
RI:  1.714 to 1.888
Birefringence:  None
SR/DR/AGG:  SR, often with ADR
Pleochroism:  None
SG:  2.72 (+0.18 / -0.05)
Routine Treatments:  None

Garnet Facts

Picture
A pair of Victorian Era antique Bohemian garnet bee brooches
Matched bee brooches set with a cluster of pyrope garnets

Garnets occur in various colors including red, orange and green.
​
A garnet bead necklace, that was found in an Egyptian grave, is dated to 3800 B.C.

Most red garnets, while beautiful, are not terribly valuable due to their relative abundance.  Green tsavorite garnets, however, can be much more expensive, especially in larger sizes.
​
​Garnet is a January birthstone and is the 2nd wedding anniversary gemstone.
​
Beautiful bee brooch set with garnets and diamonds.
Photo courtesy of Sotheby's

Garnet Varieties

Picture
ALMANDINE
Almandine Garnet three stone ring
Almandine garnet three stone ring

Color
Generally dark toned brownish orange to brownish red to purplish red, with low saturation.


Magnification
Needle-like inclusions that intersect at 70° and 110° in the same plane.  High- and low-relief crystals.  Zircon crystals with strain halos.


Spectrum
3 strong bands in the green and yellow at 505, 527 & 575nm


Fluorescence
​
Inert
DEMANTOID
Demantoid Garnet
Photo courtesy of Gems by Nomads

Color
Green through yellow green, with strong fire


Magnification
Yellowish brown, curving, radiating "horse tail" inclusions


Spectrum
Yellowish Green Stones:  Dark band at 443nm.  Rich Green Stones:  Cutoff below 443nm and fine lines at 620, 632, 693 & 700nm.


Fluorescence
​
Inert

HESSONITE
Hessonite Garnet designer in, in 18K gold, by Jane Taylor
Photo courtesy of Watchlink

Color
Medium to dark orange, to brownish orange


Magnification
Hessonite is known for its "heat wave" or "scotch in water" effect


Spectrum
Not diagnostic


Fluorescence
​
Yellow stones are inert to weak orange under LW and SW
HYDROGROSSULAR
This vintage 14K gold broch is set with a beautiful hydrogrossular garnet (often mistaken for nephrite jade), and has scattered crystal opal accents.
Hydrogrossular garnet is often mistaken for jade

Color
​
Pink or green, often brownish pink.


Magnification
Might have black, peppery looking inclusions


Spectrum
Usually shows a cutoff at 460nm


Fluorescence
Inert

PYROPE
Pair of pyrope garnet Bohemian style butterfly clips
Matched bee brooches set with a cluster of pyrope garnets

Color
Medium to dark reddish orange, red through slightly purplish red to pale pink


Magnification
Needle-like inclusions and irregular rounded crystals.


Spectrum
Chrome Pyrope:  Band at 505nm plus broad absorption at 520 through 620nm.  Possibly fine lines in the red at 685 & 687nm.  Cutoff around 490nm.  None Chrome Pyrope:  Only the 505nm band and a cutoff at 490nm.


Fluorescence
​
Inert

RHODOLITE
Vintage rhodolite garnet and diamond bypass ring in yellow gold
Rhodolite garnet twin stone bypass ring

Color
Must have a purplish component


Magnification
Needle-like inclusions that intersect at 70° and 110° in the same plane.  High- and low-relief crystals.  Zircon crystals with strain halos.


Spectrum
3 strong bands in the green and yellow at 505, 527 & 575nm


Fluorescence
​
Inert
SPESSARTINE
Vivid orange spessartine garnet and diamond ring in platinum
Spessartine garnet and diamond ring

​Color
Orange, brownish orange, yellowish orange or red orange.  Always has an orange component and never shows any purple.


Magnification
2-phase inclusions, feather-like liquid inclusions, needle-like inclusions


Spectrum
Bands at 412, 424 & 432nm, which sometimes merge to form a cutoff.  Bands at 505, 527 & 575nm.


Fluorescence
Inert
TSAVORITE
Tsavorite Garnet
Photo courtesy of King Stone Gems

Color
Medium to dark green, to yellowish green


Magnification
Partially healed fractures, fingerprints or small graphite platelets


Spectrum
Not diagnostic


Fluorescence
​
Near colorless to light green stones are inert to weak orange under LW, weak yellow-orange under SW.
UVAROVITE
Uvarovite Garnet
Photo courtesy of Gemstone Buzz

Color
​
Light to dark green through yellow-green to brownish green


Magnification
Not diagnostic.  Crystals are usually too small to facet.


Spectrum
Not diagnostic


Fluorescence
Not diagnostic


All photos courtesy of Scott Papper, GIA GG, AJP, CMA (NAJA)

  • HOME
  • ABOUT
  • SHOP
  • SERVICES
    • APPRAISALS
    • EXPERT WITNESS TESTIMONY
    • SELL YOUR JEWELRY
  • GEMOLOGY
    • GEM ENCYCLOPEDIA
    • THE ART OF GEMOLOGY
  • JEWELRY EDUCATION
    • DIAMOND FACTS
    • JEWELER DIRECTORY
    • JEWELRY PERIODS
    • POCKET WATCHES
    • NATIVE AMERICAN JEWELRY
  • GLOSSARY