80 J. B. Scrivenor — Kaolin Veins, Federated Malay States. 



Kaolin from the Kerling veins was washed and afforded deep brown 

 cassiterite and mica. JS'o tourmaline was found in tlie concentrate^, 

 nor was it seen in the field. 



Lately information has been obtained at Gopenp; and Pulai about 

 these veins in contact with the limestone. At Krainat Pulai 

 a pinnacle of limestone was exposed in January, 1916, close to 

 a kaolin vein. In the limestone was a granitic vein about 2 feet 

 wide, bordered by a pale-green massive mineral with a slightly 

 greasy feel. The granitic rock contains felspar, sometimes in 

 porphyritic crystals. Sections show that it consists of quartz, 

 orthoclase, and plagioclase, the last being abundant. One specimen 

 is finely veined by a serpentinous mineral that is probably the pale- 

 green mineral just mentioned. They show a little tourmaline and 

 some altered biotite, and also micaceous aggregates suggesting 

 piuite pseudomorphs of cordierite. Near by, in the same pinnacle, 

 are thin veins of "mountain-leather" or asbestos of the serpentine 

 variety (magnesium silicate), together with purple quartz. No vein 

 of kaolin was seen in the limestone. 



On the Kinta Tin Mines, Ltd., large quantities of the pale-green 

 massive mineral occur in juxtaposition to limestone. It is not as 

 greasy to the touch as steatite, but resembles it, and partial analysis 

 showed that it consists of magnesium and aluminium silicate. It is 

 therefore one of the ill-defined minerals allied to serpentine, and 

 differs from the kaolin in having magnesium present in addition. 



The same mineral occurs associated with kaolin in two of the 

 open-case mines on the Gopeng Consolidated land. In that on the 

 north of and close to the Khota Bahru Iload there were found with it 

 fairly large crystals of a reddish mica which contained no lithium, 

 and one specimen was found consisting of this mica, quartz, and 

 andalusite. The kaolin, close to where this specimen was taken, 

 contained dendritic markings of manganese oxide, and a small pocket 

 was found in the kaolin of black clay consisting of manganese and 

 iron oxides. Its presence was puzzling until it was discovered that 

 some at least of the pink mica at Gopeng is a manganese mica. 



In a big mine south of the Khota Bahru Road there was a good 

 section in March, 1916, of the magnesium-aluminium silicate in the 

 limestone. It formed a distinct vein about 2 feet across. Close by 

 was kaolin with quartz and wliite mica. Near by here pockets 

 of the same mineral were found in pure white kaolin. 



In the above instances there is no evidence of the kaolin 

 continuing in the limestone as kaolin. It changes to something 

 else, and the green magnesium - aluminium silicate suggests a 

 reaction between the magma that su|)plied the kaolin and magnesium 

 in the limestone. The way in which the granitic vein on Kramat 

 Pulai is bordered and veined by this mineral favours this view. 

 Oil the North Tarabun Mine, however, I have seen a very thin 

 kaolin vein in limestone, and many years ago I saw a similar 

 thing at Tambun. However, there is now strong evidence that the' 

 bigger veins do not go down into the limestone as kaolin, and one 

 naturally wants to know how they were formed, and the first 

 explanation that presents itself is that they are veins that were 



