Rhodolite

saf-ahyuh r
January Birthstone

Unusually striking, rhodolite is a naturally occurring blend of almandite and pyrope garnet. While raspberry and grape are the most prized colors, rhodolite is also found in shades of purplish red to reddish purple. The name is derived from the Greek "rhodon"rose" and "lithos"&"stone". Rhodolite is typically found as water-worn pebbles in alluvial deposits, but it is also occasionally mined directly from host metamorphic rock. Tough, durable, never enhanced and easily cleaned, rhodolite is ideal for jewelry. Due to its bright transparent clarity, rhodolite is often cut into fantasy shapes.

Rhodolite Polished
Rhodolite Classification
Common Name Rhodolite
Species Garnet
Rhodolite Optical Properties
Transparency Translucent-Transparent
Dispersion Strength: Moderate Fire Value: 0.022
Refractive Index 1.750-1.780
Optic Character NA
Optic Sign NA
Polariscope Reaction Singly Refractive (SR) With ADR
Fluorescence SWUV: Inert
LWUV: Inert
CCF Reaction May appear reddish
Pleochroism None
Rhodolite Characteristic Physical Properties
Hardness 7-7.5
Streak White
Specific Gravity 3.740-3.940 Range:0.1/-0.1 Typical:3.840
Toughness Good
Inclusions Rhodolite garnet is a type II clarity stone. Needle like inclusions, zircon crystals with stain halos and irregular rounded included crystals that might be zircon or apatite.
Luster Vitreous
Stability Good
Fracture Conchoidal
Cleavage None
Rhodolite Chemistry & Crystallography
Chemical Name magnesium iron aluminum silicate
Chemical Formula ((Mg,Fe)3AL2(SiO4)3)
Crystal System Cubic
Chemistry Classification Silicate

Rhodolite Colors

  • Pink Rhodolite Pink
  • Red Rhodolite Red
  • Pink Rhodolite Pink
  • Purple Rhodolite Purple
  • Red Rhodolite Red

Alternate Names

Grape Color Garnet, Raspberry Garnet

Countries of Origin

Tanzania, United Republic Of; Afghanistan; United States of America (the); Sri Lanka; Madagascar; Zambia; Kenya; Thailand; French Polynesia; India; Mozambique; Unknown; China; Brazil; South Africa; Nigeria

History

Rhodolite was first described in the article On Rhodolite, a New Variety of Garnet by W.E. Hidden and J.H. Pratt in 1898 in the American Journal of Science. Most material today comes from the "Mozambique Belt" in Africa.

Care

Normal Care

Related Videos

Sisk Gemology Reference

Showcasing 200 gemstones in over 1,000 pages and accompanied by more than 2,000 photos, The Sisk Gemology Reference is a must-have in every collector’s library. Each comprehensive, three-volume set features state-of-the-art photography, detailed illustrations, and scientifically precise descriptions to create an entrancing experience for gemstone amateurs and afficionados alike.

Shop Now

 

Optical Phenomena

Star or Cat's-Eye Rhodolite

Star or cat’s-eye rhodolite garnet exhibits optical phenomenon when light within the gem reflects off the rutile inclusions, creating narrow bands of light. When two or more intersecting bands appear, a star pattern is formed. Depending on the crystal, the star may have four or six rays. Stones have been reported with diasterism where both a 4-ray and a 6-ray star can be seen depending on the light orientation. The phenomenon comes from needle-like inclusions oriented at 70 and 110 degrees angles. When only one band forms, it is classified as a "cat's eye". Rhodolite star garnet comes from Kangala Mine, in the Tiriri mining district, Tanzania. The largest stone found from the Kangala Mine is 15.60ct.

Star or Cat's-Eye Rhodolite Rhodolite
Star or Cat's-Eye Rhodolite Classification
Common Name Star or Cat's-Eye Rhodolite
Star or Cat's-Eye Rhodolite Optical Properties
CCF Reaction May appear reddish
Star or Cat's-Eye Rhodolite Characteristic Physical properties
Specific Gravity 3.74
Toughness Fair
Inclusions Pyrope-almandine garnet is a type II clarity stone. Needle like inclusions produce 4 to 6 rayed stars and will sometimes show both in well-cut stones. Stones might have zircon crystals with stain halos and irregular rounded included crystals that might be zircon or apatite.
Tim Matthews

Author

Tim Matthews

Tim Matthews is President and Chief Executive Officer of Jewelry Television® (JTV), as well as a member of the company's Board of Directors. He oversees and leads all aspects of the company's powerful omni-digital retail platform that uniquely specializes in fine jewelry and gemstones. His passion for business and gemstones has led him to become a recognized expert in the field of gemology. He is a life member of the Gemmological Association of Great Britain (Gem-A) and has earned Gem-A's highest degrees, the Gemmology (FGA) and Diamond (DGA) diplomas. He is also a Graduate Gemologist (GG) of the Gemological Institute of America (GIA) and has also completed GIA's Graduate Diplomas in Diamonds, Colored Stones and Pearls. Under his leadership, JTV has become the leader in the sourcing and selling of color gemstones and jewelry.

This page was created on June 27, 2014.

This page was last edited on October 24, 2019.