Kerala State is endowed with a number of occurrences/deposits of minerals such as heavy mineral sands (llmenite, rutile, zircon, monazite, sillimanite), gold, iron ore, bauxite, graphite, china clay, fire clay, tile, brick clay, silica sand, lignite, limestone, limeshell, dimension stone (granite), gemstones, magnesite, steatite etc. However, mining activities on large scale are confined mainly to a few minerals-Heavy Mineral Sands, China Clay and to a lesser extent limestone/limeshell, silica sand and granite. In fact, heavy mineral sand and china clay contribute more than 90% of the total value of mineral production in the State.

 

Mineral Based Industries in the State

             The State owns mineral deposits like placers, china clay (kaolin), limestone, limeshell, silica sand, bauxite, graphite, iron ore, granite etc. The major mineral based industries like Indian Rare Earths Ltd., Chavara, Kerala Minerals and Metals Ltd., Chavara, Malabar Cements, Walayar, Travancore cements Ltd., Kottayam, Kundara Ceramics, Kollam, English Indian Clays Ltd. (EICL), Thiruvananthapuram, Excel Glass Industry, Alappuzha, Kerala Clays and Ceramic Products Ltd., Palayangadi, Kannur are some of the mineral based industries working in the State since several years. The resources of beautiful ornamental granites in the state are being exported to different countries.

 

Details of Individual Mineral Deposits

 

1. Mineral Sand: The Heavy Mineral Sand deposits in Kerala contain an assemblage of Ilmenite, Rutile, Leucoxene, Monazite, Zircon and Sillimanite. The State possesses one of the world class deposits of mineral sands in the coastal tracts between Neendakara and Kayamkulam. This, commonly known as the Chavara deposit, after the main locality, covers a total length of 22 km and a width of about 8 km in the northern side and 6 km in the southern side. The Chavara barrier beach portion contains concentration of heavy minerals above 60%. The Chavara deposit is estimated to contain 127 million tonnes of heavy minerals with ilmenite content of 80 million tonnes from the total reserve of raw sand of the order of 1400 million tonnes. In the northern portion beyond Kayamkulam Pozhi extending up to Thottappally in Alappuzha district, the total reserve of heavy minerals estimated to the order of 17 million tonnes with ilmenite content of 9 million tonnes from the raw sand of 242 million tonnes.

             Chavara barrier beach with a width of 225 m is divided into 8 blocks numbered I to VIII for separating ilmenite for the manufacture of TiO₂. The blocks are apportioned between Kerala Minerals and Metals Ltd. (KMML), a State Government undertaking and Indian Rare Earths Ltd. (IRE), a Government of India enterprise under the Department of Atomic Energy. Apart from the Chavara heavy mineral deposits a number of heavy mineral placers have been delineated in different parts of the State.

No	Locality	Total heavy Minerals (in MT)	Ilmenite (in MT)	Rutile (in MT)	Zircon (in MT)	Monazite (in MT)	Sillimanite (in MT)
1	Chavara Major Deposit	127.09	79.45	5.38	4.82	0.82	28.72
2	Northern contiguity of Chavara Deposit	16.93	9.03	0.64	0.40	0.17	5.66
3	Southern Kerala	1.83	1.15	0.11	0.12	0.05	0.27
4	Northern Kerala	3.35	0.53	0.01	0.05	0.003	0.80

 

2. Gold: Gold occurs in Kerala both as primary and placer deposits. The known occurrences are mainly in Wayanad- Nilambur regions. Discovery of gold in Attapady valley of Palakkad district is new and promising. Mining activity in the Wayanad Gold Field was abandoned in the early part of the 20th century. The main reason for this appears to be the discovery of the very rich gold deposits in Kolar Gold Field in Karnataka around that time. Investigaiton/exploration initiated by the Geological Survey of India (GSI) during the 1950's and 1960's concluded that the Wayanad Gold Field deserves more detailed studies and that exploratory mining in selected Department of Mining and Geology, Govt. of Kerala projects could prove to be economically workable. Following this, the United Nations assisted Kerala Mineral Exploration & Development Project of the State (now merged with Department of Mining and Geology) studied the gold placers in Chaliyar and Punnapuzha rivers draining Nilambur valley. Exploration for primary gold was also taken up which resulted in delineating the Maruda prospect. Two other prospects of interest have also been identified close to Maruda viz. Mannucheeni and Thannikkadavu.

             Department of Mining and Geology through a detailed investigation has established a reserve of 0.55 million tonnes of grade of 4g/tonne of gold in Marudp, Nilambur, Malappuram District. Further exploration is required for planning a commercial venture for mining and extraction of gold.

 

3. Iron Ore: Five iron ore deposits of banded magnetite quartzite type have been identified in Kozhikode District and one in Malappuram District. Geological Survey of India/Department of Mining and Geology, National Mineral Development Corporation (NMDC) and United Nations assisted Kerala Mineral Exploration & Development Project have explored the deposits of iron ores in these areas. These deposits are estimated to contain 84 million tonnes of reserve (geological reserves) with iron content varying from 32 to 41 %.  The reserves and the percent of Fe content are as follows 

Locality	Oxidised(MT)	% of Fe	Unoxidised(MT)	% of Fe	Total (MT)
Eleyettimala	14.7	39.4	4.5	31.5	19.2
Naduvallur	6.1	39.8	3.7	33.7	9.8
Nanminda	4.3	41.2	-	-	43
Cheruppa	3.2	35.5	7.5	31.7	10.7
Alampara	9	35.6	26.2	35.2	35.2
Korattimala	1.9	37.7	2.5	33.6	4.4

 

 

4. Bauxite: Bauxite occurs in close association with laterite all along the west coast of the State. Traces of bauxite are seen in almost all laterite cappings. But bauxite deposits of economic significance in south Kerala are a few and are located at Sooranad, Vadakkumuri, Chittavattom, and Adichanallur in Kollam district and Mangalapuram, Chilambil, Sasthavattom and Attipra areas of Thiruvananthapuram district. Geological Survey of India (GSI) and Mineral Exploration Corporation Ltd. (MECL) have conducted extensive studies of bauxite occurrence of Kasargod and Kannur districts in North Kerala during the period between 1968-74 including geological mapping, pitting, drilling and sampling. Based on various investigations, the total bauxite reserves in the State are estimated at 12.5 million tonnes. The largest bauxite deposits are in Nileswaram with a reserve of 5.32 million tonnes of grade around 45% AI2O₃ and SiO₂ less than 5%.

 

5. China Clay: China clay (kaolin) consisting dominantly of kaolinite is one of the most sophisticated industrial minerals with a host of applications, viz., in ceramics, refractories, paper coating, filler for rubber, insecticides, cement, paint, textiles, fertilizers and others including abrasives, asbestos products, fibreglass, chemicals, cosmetics, pharmaceuticals, electrical ware, foundry and glass. The Department of Mining and Geology through their past investigation campaigns in parts of Kerala, identified two major china clay zones viz., the southern china clay zone between Thiruvananthapuram and Kundara (Thiruvananthapuram and Kollam districts) and the northern china clay zone between Kannapuram Madayi-Cheruthazham in Kannur district to Nileswarm-Manjeshwaram in Kasargod district. An estimated reserve of 172 million tonnes (probable reserve of 80 million tonnes and possible reserve of 92 million tonnes) of china clay of sedimentary and residual origin has been arrived at. Kerala china clay is one of the finest quality clay and is world class. In fact, Kaolin marketed by English Indian Clays Ltd. (EICL), Thiruvananthapuram claims to have similar or even better properties compared to imported clays.

 

6. Fire Clay: The fire clay occurrences are in association with Tertiary sediments in the coastal land and the inferred reserve stands at 11.50 million tonnes. However, this resource is waiting to be exploited.

 

7. Graphite: Graphite occurs in nature in the form of vein, dissemination (flaky) and amorphous variety. The first two types of occurrences are found in Kerala. The vein-type graphite mined earlier around Veli, Vellanad and Changa is confined only to the Thiruvananthapuram district. The flake type of graphite is extensive in occurrence in Thiruvananthapuram, Kollam, Kottayam, Idukki and Ernakulam districts which have been studied by Geological Survey of India and are quite akin to the celebrated flaky graphite mined in the Malagasy Republic. The graphite occurs as thin flakes distributed more or less evenly in the rock constituting on an average about 5%-10% of the bulk of the rock, although rich pockets are not uncommon. The studies in various laboratories in the country and abroad in respect of the bulk samples collected from the flaky graphite deposits of Vadakode, Nagapuzha (Muvattupuzha taluk, Ernakulam district) and Chirakkadavu (Kanjirappally taluk, Kottayam district) point to good beneficiation characteristics, a high recovery of fixed carbon (about 85%) and preservation of suitable flake size facilitating their use in key value added industrial application like crucible manufacture etc. The reserve position in respect of the flaky graphite deposits of Ernakulam and Kottayam districts are given below 

	Nagapuzha	Vadakode	Chirakkadavu	Total
Ore reserve (tonnes)	1059352	5050938	700000	6810920
Grade (%c carbon)	7.3	5	3	-
Recoverable graphite (tonnes)	43000	24000	16000	83800
Concentrate grade (%  carbon)	89	91	88	-
Recovery	79	80	80	-

 

 

8. Silica Sand: The coastal tract between Alappuzha and Aroor in Alappuzha District contain extensive deposits of silica sand. The best deposits are confined to the narrow strip of land sandwiched on either side by Vembanad lake and stretching from Cherthala to Arookutti over a distance of about 35 km. Besides there are also smaller deposits in other districts of Kerala. The sand deposit comprises of flat to gently dipping sandy stretches, generally about 5m above Mean Sea Level

 

Vertical sequence
0-0.75 m below ground level	White sand mixed with soil
0.75-2.50 m below ground level	White sand
2.50-10.00 m below ground level	Brown sand

 

Reserves of Deposit:  Based on the recent appraisal carried out by the Department of Mining and Geology over the open area likely to be available for mining, the inferred reserve of silica sand in the villages are estimated as below 

Village	Approximate area in hectares	Reserve in million tones
Pallipuram	300	18.40
Thycauttuserry	120	6.50
Panavally	50	3.50
Total	470	28.40

 

9. Lime Stone

(i) Crystalline Limestone: Kerala State is deficient in crystalline limestone and only a few bands of crystalline limestone in Palakkad and Idukki districts have been located in addition to the limestone deposit proved at Pandarathu, Walayar, Palakkad district. The Pandarathu limestone deposit (24 million tonnes) is now the captive mine producing limestone for M/s. Malabar Cements Ltd., the Portland cement plant in Kerala. A number of small bands have also been identified in other localities in Nattuvanki, Athurasram, Vannamadai, Thavalam in Palakkad district and in a few localities in Idukki district.

(ii) Kankar Limestone: Limestone of Kankar variety has been reported from Chittoor- Kozhinjampara area in Palakkad district. The economic significance of low-grade limestone has not been indicated by the studies conducted so far. The 16 square kilometre area between Thavalam and near Anaiketty shows that kankar caps the amphibolite over 0.3 km².

(iii) Fossiliferous Limestone: Fossiliferous Limestone is known to occur in various parts of Kollam district such as Kallurkadavu, Mughathala, Kannanallur, Kottiyam, Mayyanad, Nedumgandam and Edava in Thiruvananthapuram district. The occurrence of shell limestone is in the form of discontinuous lenses intercalated with black carbonaceous clay in the Tertiary formations.

 

10. Lime Shell: The State is deficient in high-grade limestone. Consequently the requirement of lime for chemical industry is depended on the lime shell resources occurring in the backwaters/estuaries, river mouths and lagoons along the coastal tract. By far the largest reserves of lime shell are known to occur in Vembanad lake and adjoining portions comprising parts of Alappuzha, Ernakulam and Kottayam Districts. The Department of Mining and Geology by its detailed investigation in certain parts of Vembanad lake and adjoining areas have established a reserve of 3.29 million tonnes as shown below. 

Locality	Reserve in million tones
Vembanad Lake	2.50
Kualsekharamanagalam	0.18
Pallipuram	0.10
Vechoorpadam	0.26
Thannirmukkom	0.25

                       

             The lime shell resources next in importance to Vembanad lake are those in Kannur and Kasargod districts in North Kerala. The department had also investigated on the occurrence of limeshell in Thrissur, Malappuram and Kannur districts and the reserves indicated are as follows. 

Area	Reserve in million tones
Thrissur District: Naduvullikara, Vadanapalli,  Chettuva, and Kappad	0.33
Kannur District: Payyannur, Cheruvathur, and  Thrikkarippur	0.29
Malapuram District: Kanhiramukku,  Iswaramangalam, and Edappal	0.14

                   

11. Magnesite: A total possible reserve of 0.037 million tonnes has been estimated in Mulli-Salayur areas, Attappadi in Palakkad District by the Department of Mining and Geology. In Salayur area, magnesite veins varying in thickness from 10 to 30 m were observed in pits. The average recovery of magnesite was assessed as 100 kg/m³ of magnesite-bearing rocks and samples on analysis were found to contain 43.05 to 46.73% MgO, 1.51 to 6.59% of Si0₂ and 0.29 to 0.59% of CaO.

 

12. Steatite/Talc: It is consumed in many manufacturing industries of paper, insecticide, textile, fertilizers, ceramics, rubber products, cement, asbestos etc. Several steatite occurrences have been identified in Thalassery Taluk of Kannur district. The total reserves estimated are of the order of 7.94 million tonnes.

 

13.Gemstones: The exploration carried out for gemstone occurrences in Thiruvananthapuram and Kollam Districts between 1978 and 1980 by the erstwhile Kerala Mineral Exploration & Development Project has ascertained a wide range of gemstones comprising Chrysoberyl, Cat's eye, Alexandrite, Ruby, Sapphire, Beryl, Aquamarine, Topaz, Kornerupine, Zircon, Sphene, Spinel, Garnet etc. The pegmatite exposures and most of the gravel beds in Thiruvananthapuram district and southern part of Kollam district were sampled and analysed to ascertain the presence of gem. Although the source of Chrysoberyl gem in the river gravel was identified to be the pegmatites, no corundum bearing rocks were identified in Thiruvananthapuram district. The available information on the occurrence of gemstones in southern Kerala points to the predominance of chrysoberyl over other species of gemstones.

             There are three different geological setting in which gemstones occurs in Kerala viz- (i) the pegmatites traversing the crystalline rocks (ii) in association with gravels in the river channels of the present day (iii) in the older gravels which are often consolidated and lateritised. These settings have fairly extensive geographical distribution in Thiruvananthapuram district, the localities of importance are Andoorkonam, Aruvikkara, Balaramapuram, Bonaccord Estate Braemore Estate, Changa, Chullimanur, Madathara, Manickkal, Pirappancode, Venjaramoodu, Venganoor, Vembayam, Thonnakkal, Uzhamalakkal, Manvila, Mudakkal, Nedumangad, Vellanad, Nettani, Ooroottambalam, Pothencode and in Kollam, the main gem bearing localities are Adukkalamula, Podiattuvila,Kulathupuzha, and  Talachira. Besides these localities several stretches of rivers like Kallar- Vamanapuram Ar, Karamana Ar, Neyyar in Thiruvanathapuram District and Kulathupuzha, Kallada rivers in Kollam district are also subjected to sporadic mining activities, though there is no legalized gem mining in the State.

 

14. Mica: Two types of mica are available in Kerala- phlogopite and muscovite mica. But mining has not advanced so far. The geographical distribution of mica includes Punalur in Kollam district and Kayana in Kozhikkode districts of Kerala.

 

15.Silver Sand: The geographical distribution of mica includes Pallithura, Kazhakkuttom, Menamkulam in Trivandrum district, Pallipuram, Thycattussery, Varanad in Alppuzha district. 

 

Mineral Map of Kerala.