Liddicoatite

Big Photo

Madagascar
1.25 carats
© Mineral Classics

Liddicoatite is a calcium lithium tourmaline species, named after US gemologist R. T. Liddicoat.

Liddicoatite forms green, red, pink, purple, and and blue, sometimes white, colorless, black, brown, yellow, and orange elongated prismatic crystals. Crystals are frequently multicolored, containing two or more distinct colours. It may also have internal colour zoning and banding.

Large crystals of Liddicoatite are often cut and polished into slices, with the multicolored designs and forms. Faceted material is rare because of its limited occurrences, and because most gem material is not tested to determine what type of tourmaline mineral it is - so will be labelled as Tourmaline regardless of whether it is Liddicoatite, Elbiate or another type of Tourmaline.

Liddicoatite Gemstones by Colour

This table shows the variety of hues this gemstone can be found in. Click on a photo for more information.
 

Liddicoatite Gemstones by Size

This table shows distribution of Liddicoatite gemstone sizes that are listed on this site. This can give a good indication as to the general availability of this gemstone in different sizes.
Contributed photos
Lightest:0.96 cts
Heaviest:1.70 cts
Average:1.30 cts
Total photos:3
Do you have a larger Liddicoatite? Why not upload a photo?
0.96ct to 1.03ct1.03ct to 1.11ct1.11ct to 1.18ct1.18ct to 1.26ct1.26ct to 1.33ct1.33ct to 1.40ct1.40ct to 1.48ct1.48ct to 1.55ct1.55ct to 1.63ct1.63ct to 1.70ct
General Information
A variety or type of:Tourmaline
Chemical Formula
Ca(Li
 
2
Al)Al
 
6
(Si
 
6
O
 
18
)(BO
 
3
)
 
3
(OH)
 
3
(OH)
Gemdat.org, Management Team (2012)
Physical Properties of Liddicoatite
Mohs Hardness7.5 to 0
Anthony et al, Handbook of mineralogy (2001)
Specific Gravity3.02
Anthony et al, Handbook of mineralogy (2001)
TenacityBrittle
Anthony et al, Handbook of mineralogy (2001)
Cleavage QualityPoor
Anthony et al, Handbook of mineralogy (2001)
FractureUneven,Conchoidal
Anthony et al, Handbook of mineralogy (2001)
Optical Properties of Liddicoatite
Optical CharacterUniaxial/-
Anthony et al, Handbook of mineralogy (2001)
PleochroismStrong: dark brown - light brown
Anthony et al, Handbook of mineralogy (2001)
Colour
Colour (General)Brown, green, pink, red, blue; commonly zoned parallel to pyramid faces.
Anthony et al, Handbook of mineralogy (2001)
Causes of ColourGreen, Fe2+ and Ti4+ in octahedral coordination, influence of various charge transfer processes involving iron is a distinct possibility. Yellow-green, Mn2+-O-Ti4+ charge transfer. Greenish yellow, Mn2+ in octahedral coordination (rare). Orange, yellow + pink. Pink to red, related to manganese, generally believed to be due to Mn3+ in octahedral coordination, sometimes caused by irradiation. Brown, Fe2+Ti4+ charge transfer
W. William Hanneman, Pragmatic Spectroscopy For Gemologists (2011)
TransparencyTransparent,Translucent
Anthony et al, Handbook of mineralogy (2001)
LustreVitreous
Anthony et al, Handbook of mineralogy (2001) Vitreous on fractures.
Crystallography of Liddicoatite
Crystal SystemHexagonal
Anthony et al, Handbook of mineralogy (2001)
HabitCrystals stout prismatic, with curved convex trigonal outline, deeply striated, to 25 cm.
Anthony et al, Handbook of mineralogy (2001)
Geological Environment
Where found:Detrital in soil, an apparent product of the local pegmatites.
Anthony et al, Handbook of mineralogy (2001)
Further Information
Mineral information:Liddicoatite information at mindat.org
Significant Gem Localities
Sri Lanka
 
  • Sabaragamuwa Province
    • Ratnapura District
      • Ratnapura
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