Elbaite

Cyclosilicate, mineral


title: "Elbaite" type: doc version: 1 created: 2026-02-28 author: "Wikipedia contributors" status: active scope: public tags: ["sodium-minerals", "lithium-minerals", "cyclosilicates", "trigonal-minerals", "minerals-in-space-group-160", "gemstones", "tourmalines"] description: "Cyclosilicate, mineral" topic_path: "general/sodium-minerals" source: "https://en.wikipedia.org/wiki/Elbaite" license: "CC BY-SA 4.0" wikipedia_page_id: 0 wikipedia_revision_id: 0

::summary Cyclosilicate, mineral ::

::data[format=table title="Infobox mineral"]

FieldValue
nameElbaite
categoryCyclosilicate
boxbgcolor#7aaa11
boxtextcolor#FFFFFF
imageElbaite with albite - São José da Safira, Minas Gerais, Brazil.jpg
imagesize280px
formulaNa(Li1.5Al1.5)Al6Si6O18(BO3)3(OH)4
IMAsymbolElb
strunz9.CK.05
systemTrigonal
classDitrigonal pyramidal (3m)
H–M symbol: (3m)
symmetryR3m
colorGreen, red to pink, blue, orange, yellow, colorless, multicolored
habitPrismatic; striated
cleavagePoor/indistinct on {1120} and {1011}
fractureSub-conchoidal
mohs
lusterVitreous
refractivenω = 1.635–1.650, nε = 1.615–1.632
opticalpropUniaxial (−); moderate relief
birefringenceδ = 0.020
streakWhite
density2.9–3.2
diaphaneityTransparent to opaque
otherpiezoelectric and pyroelectric
references
var1Achroite
var2Indicolite
var3Rubellite
var4Verdelite
::

| name = Elbaite | category = Cyclosilicate | boxbgcolor = #7aaa11 | boxtextcolor = #FFFFFF | image = Elbaite with albite - São José da Safira, Minas Gerais, Brazil.jpg | imagesize = 280px | caption = | formula = Na(Li1.5Al1.5)Al6Si6O18(BO3)3(OH)4 | IMAsymbol = Elb | molweight = | strunz = 9.CK.05 | system = Trigonal | class = Ditrigonal pyramidal (3m) H–M symbol: (3m) | symmetry = R3m | color = Green, red to pink, blue, orange, yellow, colorless, multicolored | habit = Prismatic; striated | cleavage = Poor/indistinct on {1120} and {1011} | fracture = Sub-conchoidal | mohs = | luster = Vitreous | refractive = nω = 1.635–1.650, nε = 1.615–1.632 | opticalprop = Uniaxial (−); moderate relief | birefringence = δ = 0.020 | streak = White | density = 2.9–3.2 | diaphaneity = Transparent to opaque | other = piezoelectric and pyroelectric | references = | var1 = Achroite | var1text = colorless | var2 = Indicolite | var2text = blue | var3 = Rubellite | var3text = red to pink | var4 = Verdelite | var4text = green

Elbaite, a sodium, lithium, aluminium boro-silicate, with the chemical composition Na(Li1.5Al1.5)Al6Si6O18(BO3)3(OH)4, is a mineral species belonging to the six-member ring cyclosilicate tourmaline group.

Elbaite forms three series, with dravite, with fluor-liddicoatite, and with schorl. Due to these series, specimens with the ideal endmember formula are not found occurring naturally.

As a gemstone, elbaite is a desirable member of the tourmaline group because of the variety and depth of its colours and quality of the crystals. Originally discovered on the island of Elba, Italy in 1913, it has since been found in many parts of the world. In 1994, a major locality was discovered in Canada, at O'Grady Lakes in the Yukon.

Elbaite forms in igneous and metamorphic rocks and veins in association with lepidolite, microcline, and spodumene in granite pegmatites; with andalusite and biotite in schist; and with molybdenite and cassiterite in massive hydrothermal replacement deposits.

Elbaite is allochromatic, meaning trace amounts of impurities can tint crystals, and it can be strongly pleochroic. Every color of the rainbow may be represented by elbaite, some exhibiting multicolor zonation. Microscopic acicular inclusions in some elbaite crystals show the cat's eye effect in polished cabochons.

Elbaite varieties

  • Colorless: achroite variety ()
  • Red or pinkish-red: Rubellite variety (from ruby)
  • Light blue to bluish green: Brazilian indicolite variety (from indigo)
  • Green: Brazilian verdelite variety (from emerald)
  • Watermelon tourmaline is a zoned variety with a reddish center surrounded by a green outer zone resembling watermelon rind, evident in cross-sectional slices of prisms, often displaying curved sides.

File:Tourmaline achroïte 1(Pakistan).jpg|Achroite File:Tourmaline-195614.jpg|Rubellite File:Tourmaline-Quartz-214670.jpg|Indicolite File:Turmalingruppe-Elbait-Verdelith - in Quarz aus Brasilien.JPG|Verdelite File:Elbait Turmalin DSC 5183.jpg|Watermelon tourmaline

::figure[src="https://upload.wikimedia.org/wikipedia/commons/2/28/Elbaite_at_Peabody.jpg" caption="Elbaite specimen at Yale's [[Peabody Museum of Natural History"] ::

References

References

  1. Warr, L.N.. (2021). "IMA–CNMNC approved mineral symbols". Mineralogical Magazine.
  2. [http://www.mindat.org/min-1364.html Elbaite]. Mindat
  3. [http://webmineral.com/data/Elbaite.shtml Elbaite]. Webmineral
  4. "IMA Mineral List with Database of Mineral Properties".

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sodium-mineralslithium-mineralscyclosilicatestrigonal-mineralsminerals-in-space-group-160gemstonestourmalines