CLAYS FOR CERAMIC APPLICATIONS
Clay is one of the most common sedimentary rocks and it consists of one or several minerals of kaolinite and montmorilonite group or other bedding silicates.

A major part of extracted clay in the world makes up kaolin which is used in wood-pulp and paper industry in manufacturing of china, faience and refractory products.

Georgia is not an exception as well, numerous hotbeds of ceramics making have been known here since olden days and each of them was directly connected with a clay deposit.

Earthenware or its remains are practically found in all excavations of ancient man’s sites. Particular place in the earthenware took and takes black ceramics, known since about third millennium B.C. Traditions of making ceramics of this kind are related to Etruscans culture (ancient Etruria) as well as to the culture of ancient Georgia.

Georgia during all its history has been rich in traditions of using clays in medicine and cosmetology, in manufacturing earthenware, china and faience crockery and other articles.

Georgia is rich in different types of refractory raw materials. They are represented by alumosilicates, magnesial and siliceous clays.


The clays often have impurities of accessory minerals: feldspars, quartz mica, pyroxenes, magnetite, limonite and other. The color of clays depends on the presence of iron oxides and black carbon.

On the territory of Georgia grayish - white, light-grey, dark-grey and yellow-red clays are mainly encountered. Their white and grayish-white variety is called kaolin. Deposits and shows of such clays are mainly connected with Jurassic cretaceous and tertiary rocks

Jurassic fire-clays are mainly associated with continental sediments and are situated on Georgian Block.

Chemical composition of the of some clay deposits of Georgia (%) 

 Deposit    SiO2
 Al2O3   Fe2O3  TiO2  CaO   MgO   Na2O   K2O   SO3
 P22O5   L.O.I.
Kandara
64.22
 29.51  2.15  0.12  0.51  0.58  2.00  1.03  1.75  -  1.80
Macharula  51.89  31.98 2.46
 1.15  0.81  0.18  1.44  0.25  0.88  0.05  9.69
Gelati  50.04 36.61
1.00
0.04
0.26
0.34
-
 - 1.87
-
12.65
Djvari  49.12 35.01
2.93
0.10
0.32
0.60
-
 -  -  -  11.93
Chartali  53.20 28.42
0.49
0.90
0.18
0.36
1.34
5.69
0.10
-
4.28
Tsetkhlauri-1  47.06  28.26  2.60  -  0.49  0.35  1.10    0  -  9.90
Tsetkhlauri-2
 47.58  26.98  1.42  -  0.55  1.99  2.44    trace  -  7.11
Tsetkhlauri-3
 44.60  31.60  1.80  -  0.31  0.22  3.28    trace  -  10.22
Djikhadjvari  65.64  22.32  1.74  0.90  0.44 0.96
0.36
3.25
 2.46 -
4.10
Ochkhamuri  52.50  27.72  4.43  0.12  1.90  0.65  1.53  1.63  0.71  -  10.40
MakvaneTi 57.75   27.80 1.14  0.44  0.51  0.93  2.04   2.00  0.74  0  8.14
Gogolauri  47.30  32.96  2.04  -  -  -  -  -  -  -  7.84
Eliatsminda  57.70  28.00  1.80  0.85  1.37   0.74   0.41  0.70  0.23  -  8.25
Cikarauli  64.35  23.75  15.05  1.06  0.47 0.21   0.26  0.49   -  -  8.19
Sormoni  60.85  25.85  3.18  -  1.33  0.94  0.69    0.65  -  9.24
Rioni  56.66  27.30  2.97  -  1.87  0.59  0.66    0.86  - 8.97
Zarati  58.53  22.69 4.95
 -  1.49  0.37  1.05    1.05  -  8.47
Dambludi  64.64  23.26  10.30  0.61  0.63  0.43  1.10 3.88
 0.14  -  -

More information about the clay of deposits from the table you can found here -
As a model was chosen clay from the Darbazi occurrence.

Preliminary laboratory studies of the Darbazi clay were conducted by geologist and free-lance consultant Gian Paolo Bertolotti (R.M. Ricerche Minerarie s.r.l. laboratory, Lozzolo, Italy). Research report and expert's opinion see here