Click on a letter above to view the list of gems.    

  

 


Kaolinite (inclusions in Quartz)
Current inventory: 0 gems
 

Quartz with Kaolinite inclusions

  
Kaolinite was named in 1637 by Chinese scientist and encyclopedist Song Yingxing (1587-1666) for the ancient Chinese type locality at the "Kao-Ling" Mine (from Gaoling, meaning high ridge), Jingdezhen Prefecture, Jiangxi Province, China.

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

 

Chemistry

 

 

Chemical Formula:

Al2Si2O5(OH)4

 

Aluminum Silicate Hydroxide

Molecular Weight:

258.16 gm

Composition:

Aluminium

20.90 %

Al

39.50 %

Al2O3

 

Silicon

21.76 %

Si

46.55 %

SiO2

 

Hydrogen

1.56 %

H

13.96 %

H2O

 

Oxygen

55.78 %

O

 

 

 

 

100.00 %

 

100.00 %

= TOTAL OXIDE

 

 

Classification

   

   

Mineral Classification:

Silicates (Germanates)

Strunz 8th Ed. ID:

8/H.25-10

Nickel-Strunz 10th Ed. ID:

9.ED.05

 

9 : SILICATES (Germanates)
E : Phyllosilicates
D : Phyllosilicates with kaolinite layers composed of tetrahedral and octahedral nets

Related to:

Kaolinite-Serpentine Group. Dickite, Halloysite and Nacrite are polymorphs. Chemically identical to Halloysite-7Å.

Members of Group:

Kaolinite-Serpentine Group: Amesite, Antigorite, Baumite, Berthierine, Brindleyite, Caryopilite, Chrysotile, Clinochrysotile, Cronstedtite, Dickite, Fraipontite, Greenalite, Halloysite, Kaolinite, Kellyite, Lizardite, Manandonite, Nacrite, Népouite, Odinite, Orthochrysotile, Parachrysotile, Pecoraite, Webskyite 

Varieties:

Chrome-Kaolinite, Keramite (of Hunt), Parakaolinite

Synonyms:

Ancudite, Carnat, China Clay, Clayite (of Mellor), Cleîte, Collyrinum, Collyrum, Creniadite, Fireclay, Kaolin, Leucargilla, Marga Porcellana, Myelin, Neokaolin, Pholerite, Porcelain Clay, Porcelain Earth

 

 

Crystal Data

   

   

Crystallography:

Triclinic - Pedial

Crystal Habit:

Rarely as crystals, thin platy or stacked, to 2 mm. More commonly as microscopic pseudohexagonal plates and clusters of plates, aggregated into compact, claylike masses. 

Twinning:

None

 

 

Physical Properties

   

 

Cleavage:

Perfect on {001}

Fracture:

Irregular/Uneven, conchoidal, sub-conchoidal, micaceous

Tenacity:

Sectile, flexible but inelastic

Moh's Hardness:

2.0 - 2.5

Density:

2.61 - 2.68 (g/cm3)

Luminescence:

None

Radioactivity:

Not Radioactive

 

 

Optical Properties

   

   

Color:

White to tan or cream and pale-yellow; also often stained various hues of tans and browns by impurities

Transparency:

Transparent to opaque, translucent as single crystals

Luster:

Waxy, pearly to dull, earthy

Refractive Index:

1.553 - 1.570  Biaxial ( - )

Birefringence:

0.007 - 0.017

Dispersion:

Weak; r > v

Pleochroism:

None

 

 

Occurances

   

   

Geological Setting:

Replaces other aluminosilicate minerals during hydrothermal alteration and weathering. A common constituent of the clay-size fraction of sediments, where it may be formed by direct precipitation.

Common Associations:

Quartz, Feldspar, Muscovite

Common Impurities:

Fe, Mg, Na, K, Ti, Ca, H2O

Type Locality:

Gaoling Mine (Kaoling Mine), Gaoling village, Ehu town, Fuliang County, Jingdezhen Prefecture, Jiangxi Province, China

Year Discovered:

Ancient times. Known since the Yuan (Mongol) dynasty in the thirteenth century. Named in 1637

View mineral photos:

Kaolinite Mineral Photos and Locations

 

 

Unusual Gem Categories

   

   

 

Inclusions in Quartz

 

 

More Information

   

   

 

Mindat.org
Webmineral.com

 

 


Kaolinite has been known since at least the Yuan (Mongol) dynasty in the thirteenth century as "Kaolin earth". It is a "clay mineral". Clay minerals are hydrous aluminium phyllosilicates, often with variable amounts of iron, magnesium, alkali metals or alkaline earths. Kaolinite is typically white to cream or pale-yellow or may often be stained various hues of tans and browns by impurities.

Kaolinite was first properly described and named in 1637 by Chinese scientist and encyclopedist Song Yingxing (1587-1666) who lived during the late Ming Dynasty. Kaolinite was named for the ancient Chinese type locality at the "Kao-Ling" Mine (from Gaoling, meaning high ridge), Jingdezhen Prefecture, Jiangxi Province, China. Kaolinite was possibly the most important mineral in clays used in pre-historic pottery. Kaolinite was introduced to the West by a French priest in 1712.

Kaolinite is largely found in masses, in clay beds, usually with a bright white color. Kaolinite is too soft to be used as a gem on its own, but it is available as inclusions in Quartz gems. The picture above shows a faceted Quartz gem with beautiful inclusions of white Kaolinite. If you place your cursor over the picture you will see a magnified picture of white Kaolinite formations in the Quartz. This gem is from a recent find in Madagascar.

Kaolinite distribution: pure material from many localities, including: at Kauling, Kiangsi Province, China. In numerous china-clay pits in Cornwall and Devon, England. At Limoges, Haute-Vienne, France. Near Dresden, Kemmlitz, and Zettlitz, Saxony, and elsewhere in Germany. Large deposits in the Donets Basin, Ukraine. In the USA, at Macon, Bibb County, Georgia; at the Dixie Clay Company mine, and in the Lamar Pit, near Bath, Aikin County, South Carolina; near Webster, Jackson County, North Carolina; near Murfreesboro, Pike County, and at Greenwood, Sebastian County, Arkansas; from Mesa Alta, Rio Arriba County, New Mexico. At Huberdeau, Quebec, and near Walton, Nova Scotia, Canada.
 

  
Kaolin
ite gems for sale:

We have not photographed our Kaolinite gems yet. Please check back soon.
 

 


I love Sarah