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Celadonite (inclusions in Quartz)

Discovered in 1847; IMA status:  Valid (pre-IMA; Grandfathered)

Chemistry

Chemical Formula:

K(Mg,Fe²⁺)(Fe³⁺,Al)Si₄O₁₀(OH)₂

Potassium Magnesium Iron Aluminum Silicate Hydroxide

Molecular Weight:

429.02 gm

Composition:

Potassium

9.11 %

K

10.98 %

K₂O

Magnesium

4.53 %

Mg

7.52 %

MgO

Aluminum

0.63 %

Al

1.19 %

Al₂O₃

Iron

14.32 %

Fe

3.35 %

FeO / 16.75% Fe₂O₃

Silicon

26.19 %

Si

56.02 %

SiO₂

Hydrogen

0.47 %

H

4.20 %

H₂O

Oxygen

44.75 %

O

100.00 %

100.00 %

= TOTAL OXIDE

Classification

Mineral Classification:

Silicates (Germanates)

Strunz 8th Ed. ID:

8/H.10-30

Nickel-Strunz 10th Ed. ID:

9.EC.15

9 : SILICATES (Germanates)
E : Phyllosilicates
C : Phyllosilicates with mica sheets, composed of tetrahedral and octahedral nets

Related to:

Mica Group. Muscovite Subgroup. Muscovite-Celadonite Series. Polytypes: 1M. The Mg analogue of Ferroceladonite. Isostructural with: Aluminoceladonite, Chromceladonite, Ferroaluminoceladonite, Ferroceladonite, Glauconite.

Members of Group:

Mica Group: Aluminoceladonite, Anandite, Annite, Annite-Phlogopite Series, Aspidolite, Balestraite, Biotite, Bityite, Boromuscovite, Brammallite, Celadonite, Chernykhite, Chromceladonite, Chromphyllite, Clintonite, Eastonite, Ephesite, Ferroaluminoceladonite, Ferroceladonite, Ferrokinoshitalite, Fluorannite, Fluorphlogopite, Ganterite, Glauconite, Hendricksite, Illite, Kinoshitalite, Lepidolite, Luanshiweiite, Margarite, Masutomilite, Montdorite, Muscovite, Muscovite-Celadonite Series, Nanpingite, Natro-glauconite, Norrishite, Oxykinoshitalite, Oxyphlogopite, Paragonite, Phengite, Phlogopite, Polylithionite, Preiswerkite, Roscoelite, Shirokshinite, Shirozulite, Siderophyllite, Sokolovaite, Suhailite, Tainiolite, Tetraferriannite, Tetraferriphlogopite, Tobelite, Trilithionite, Voloshinite, Wonesite, Yangzhumingite, Zinnwaldite

Varieties:

None

Synonyms:

Baldogée, Celedonite, Seladonite, Verona Earth, Veronite

Crystal Data

Crystallography:

Monoclinic - Prismatic

Crystal Habit:

Minute micaceous scales or earthy aggregates.

Twinning:

None

Physical Properties

Cleavage:

Perfect on {001}

Fracture:

Clay-like fractures with no visible crystalline affinities

Tenacity:

Fragile; Friable to Unctuous

Moh's Hardness:

~2.0

Density:

2.95 - 3.05 (g/cm³)

Luminescence:

None

Radioactivity:

Barely Detectable; GRapi = 130.24 (Gamma Ray American Petroleum Institute Units)

Optical Properties

Color:

Blue-Green, Olive-Green, Apple-Green

Transparency:

Translucent to Opaque

Luster:

Waxy, Dull, Earthy

Refractive Index:

1.606 - 1.662  Biaxial ( - )

Birefringence:

0.0270

Dispersion:

Moderate; r < v

Pleochroism:

Visible; x=yellowish-green, y=green or emerald green, z=green or emerald green

Occurances

Geological Setting:

Replaces primary ferromagnesian silicate minerals in altered intermediate to mafic volcanic rocks, developed under low-grade zeolite facies metamorphism; as amygdule fillings in basalts or andesites.

Common Associations:

Montmorillonite, Clinoptilolite, Heulandite, Laumontite, Prehnite, Chlorite, Quartz, Calcite

Common Impurities:

Mn, Ca, Na

Co-Type Localities:

• Planitz, Zwickau, Saxony, Germany
• Malga Canalece, Brentonico, Mt. Baldo, Trento Province, Trentino-Alto Adige, Italy
• Tierno-Besagno, Mori, Mt. Baldo, Trento Province, Trentino-Alto Adige, Italy

Year Discovered:

1847

View mineral photos:

Celadonite Mineral Photos and Locations

More Information

Mindat.org
Webmineral.com

Celadonite was named in 1847 by German mineralogist Ernst Friedrich Glocker (1793-1858) from the French word celadon, for sea green, referring to its typical color. The mineral Glockerite was named in his honor in 1855. Glocker is credited with naming over 70 minerals including Arsenopyrite, Halite, Linarite and Sphalerite.

Celadonite is a hydrous silicate of iron and potassium that is a member of the Mica Group of minerals that also includes Lepidolite, Muscovite, Phlogopite and Polylithionite. Celadonite is usually a massive, fairly unattractive, mineral except when it is included in other minerals. One example is Indian Zeolites, such as Heulandite, colored green by Celadonite inclusions. Possibly the most beautiful example is Celadonite included Quartz from Madagascar (as seen in the picture at the top of this page). Quartz gems cut to show Celadonite phantom inclusions are particularily beautiful.

Massive Celadonite is available from many localities worldwide but gemmy examples of Celadonite included Quartz are only known from Madagascar.

Celadonite gems for sale:

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