Kyanite
By CLELAND SCOTT
0 NE of the best dollar-earners in Kenya is a non-precious mineral called kyanite, worth, since devaluation, £7 a ton at Mombasa. The demand for this mineral is world- wide and will remain constant ; most of the output goes to the U.S.A. with some to other hard-currency areas. There is a certain amount in America, but the quality is poor ; in pre-war days India produced most of what was required, but her mines are nearly worked out and no longer economic. It is a most attractive-looking mineral, blue, grey and red in colour, found in crystals, some of which from the Indian mines were used as gem-stones. Its greatest value is its incredibly high melting point, 1,200° Centigrade. But in order to get'the full value from it, kyanite has to be calcined until it becomes mullite, when it expands, and 10 per cent. of this can stand a temperature of between 1,800 and 1,900 degrees. 1 .:ullite is extremely durable, and is used in the firebricks of any oven that has to stand constantly high temperatures ; it is used in all refractories and electric furnaces. Like most..things in life, there is kyanite and kyanite. To be commercially salable, the alumina content must be 59 per cent. to 61 per cent. As you sell it by the ton, it is uneconomic if you have a too-long road-haul combined with a lengthy rail-freight ; it can stand 25 miles' road-transport together with a rail-haul of 170 miles. Its importance can be judged by the fact that Kenya is getting a dollar loan in order to purchase the necessary machinery for its mining and for turning it into mullite.
During 1948 my partner Fupi and I were given a sample and a hint as to where we might find a deposit of kyanite. The area we wanted to prospect had, a month previously, been gazetted as the Fsavo National Park, 7,000 square miles of country. We were in entire sympathy with the creation of National Parks, and in the past I had actually driven the lorry containing the camp-kit of the committee when we were investigating areas for possible parks. We were given permission to prospect, and to obviate any, possibility of having to shoot any bad-tempered pachyderm we took no rifles. We knew that the elephant would not molest us without cause, and the same applied to leopard or lion. Although I was moderately certain that the rhino of those parts, not having been harried by Wakamba poachers, were reasonably docile, I also knew that there were a lot• of them just where we wanted to search ; one cannot argue with two tons of flustered rhino, which at any time are the stupidest of all the dangerous game.
We drove parallel to the head-waters of the Tsavo river ; in the vicinity a large company was busy extracting kyanite from a low hill. We drove past it, and at once noticed two other hills in a line with it. One was smaller and the other very much larger ; they were roughly four miles apart and four miles from it. We established ourselves in a delightfully shady camp on the river, and after lunch we drove down-stream and investigated the far side. The hills were all lava from Mt. Kilimanjaro, which towered in front ; in our peregrinations we put up three rhino. That night the elephant serenaded us with joyous trumpetings within seventy yards of camp. It seemed impossible that the established company had not thoroughly prospected the big and the little hill ; but, knowing our Kenya and its inhabitants, and for the sake of maybe a wasted morning, we decided to examine the bigger one. We were trudging up the slopes towards a definite saddle when Fupi spotted the first small boulder—large stone is more accurate—of kyanite peeping from the ground ; there was no mistaking those blue dagger-like crystals. We found more boulders near the saddle and more over the far side together with a somnolent rhino ; other boulders ran down the main shoulder. We then forced our way through very dense bush and searched along the main hill on a gradient of almost one in two. For a time we drew blank ; Fupi saw what she thought was a vast boulder of some kind, so went closer to see if it held kyanite (lots• didn't), and realised that it was a rhino, which obligingly crashed downhill cascading rocks and stones. Throughout the entire length of the hill, over a mile in length and all of 700 feet high, we came across pockets of kyanite boulders of excellent quality. Next day we tackled the smaller hill and found it held some, too.
In Kenya a non-precious mineral claim is 200 yards long by 300 yards wide. It is true we did not have to compete with hordes •i of other miners during our pegging operations, but we had plenty of difficulty and excitement, the latter provided mainly by rhino. I had heard that a little judicious hand-clapping and shouting would turn them. On one occasion we proved this to be true ; the rhino was about to blunder into us, not we into him. We never got seriously charged. The bush was so thick, mainly of the hooked or wait-a- bit variety, the tree-and-vine types, that even at 20 yards it was often impossible to see a white cloth wrapped round a stick. Conse-. quently holding one's line on a compass-bearing was poor fun and difficult. While working on the end claim of the small hill, we noticed a small kopje, so stopped taking our line to look it over, and found the largest and best-quality boulders of all, so quickly pegged another eight claims, making thirty-nine in all.
These hills of ours were fourteen miles from where we could get the lorry to the river-bank. First the water had to be ladled into 44-gallon drums, so it was rather precious. By the time it had bathed us, washed our clothes and helped to cement in the corner- beacons we reckoned it owed us nothing. At first we spent out time prospecting our own claims with hardly any labour. Wit finally picked on what we always called the little kopje as the best and easiest area to work, as we could get lorries right up to tha workings. In time we had a staff of thirty-odd boys, and began.. serious quarrying rather than mining. We had a great deal to learn, and never got really ambitious as regards letting off many fuses at one time, six being our limit, and then the match often broke on number four, resulting at times in an abandonment of number six, , followed by a very hurried dash to cover under some overhanging rock before the first sticks of gelignite went off Kyanite being so hard, hand-drilling is slow ; we split the varying boulders with a , charge, and then boys using the heavy hammers further broke up the bigger segments into manageable lumps. Then these had to be weighed and stacked in piles of a ton. The next job was to cart it to Taveta, where there was a station—a haul of twenty-two miles., In many ways kyanite can be described as a perverse mineral, . since you never find a nice solid face as with coal. Some boulders flatter only to deceive, as they have what amounts to a " skin " of kyanite, but until you have drilled holes and blown it open you cannot tell. It exists in lenses, and you often have to shift a great deal of other rocks to reach your lens. Other varieties at a casual glance look all right but turn out to be mainly schist, which as it lies is useless ; to win the pure kyanite from this means a great deal of very expensive machinery, lots of water and a large amount of work. Every lump of kyanite has to be looked over carefully, since if you let past schist or quartz—some boulders have lots of veins running through them—the 'alumina content would drop below 59 per cent. If this happened, you could then tip it into the sea after having paid road- and rail-transport. Each shipment has first to be sampled and analysed by the Mines Department in Nairobi, so you•have to be eternally on your toes.
Within a year of Fupi spotting the first boulder we sold out after getting production up to a tonnage of 250 a month, so we may be said to have had true beginner's luck. It was all most thrilling, especially until we had our claims registered. We attribute our good fortune mainly to the cantankerous old rhino. Around the big hill runs a main elephant path, and if one stuck to that one would come away with the impression that there was but little kyanite and of poor quality, so " barging about in the bash " paid us good dividends. We knew that one man had looked around vaguely, besides an elderly Government geologist. The former had found the place so thick with rhino that he had not looked thoroughly, and turned down a perfectly good mine, even though in those days you could shoot if necessary.
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