KČT collectors´ cards
may be purchased at our gallery
Londýnská 55
We are looking forward to your visit.





Private fishing range
Come to us to catch some.
Two ponds,  Accommodation,  Club room
www.dobravoda.org




Tourmalines - Mozambique

Continued

7) tantalite crystals weighing several kilograms, from the locality MuianeOn the second day we go visit Jeremy. For the first time it's a bit hot. About thirty-six degrees (Celsius) in the shade. Jeremy is a fun guy and his task is to determine and verify the yield and reserves of tantalum - niobium mineral deposits. Black workers dig trenches about a meter deep across the "white mountain". They take samples and separate them.
8) indigolite weighing over 1 kg in Jirka's hand - unfortunately this one didn't end up in our collectionJeremy also showed us some treasures. Of course crystals of tantalite, some of truly global parameters. Also tourmalines, for example a closed one-kilogram indigolite smoothly passing into rubellite. (photo no. 7, photo no. 8) It made our throats feel parched! But the miners are South Africans so Jeremy naturally has in his fridge - pilsner beer.
9) Muiane - adit 46 m deep, dug by natives, at the end of which the finest gem rubellites were found and where several natives suffocatedFinally we set off for the locality. We climb the steep road and in the glowing sun the white colour of kaolin stings the eyes until they start watering. But they are tears of joy, as there's an interesting stone every five steps. A fragment of a crystal intergrown by verdelite, a piece of a nice smoky quartz crystal, the imprint and remnant of a rubellite in milky quartz, two cm wide, length…? Jumping from stone to stone we reach the top of the mountain. Slowly the distances between us grow, each one looks for "his spot" to dig. We meet in about half an hour. We are dried up from the sun, but everyone found something. Luboš has nice double-sided smoky quartz crystals, Pavel raspberry rubellites up to three centimetres and I got unusual crystals of purple lepidolite.
10) Muiane - adit 46 m deep, dug by natives, at the end of which the finest gem rubellites were found and where several natives suffocatedTogether we go round the mountain and climb down two levels on the north side. There is a glen hollowed-out by water with a bit of shade. We find an opening in the wall. This is where the natives lowered themselves into the interior of the mountain. Carefully we look in, but see no ending. Tourmaline remnants are visible on the tunnel walls. (photo no. 9, photo no. 10) Later we hear from Alexander that the adit is over forty meters deep and several diggers died in it. They suffocated. But from the twenty-sixth meter they found double-sided tourmalines up to fifteen centimetres long. They were gem quality rubellites, some with an indigolite centre. We go further down the glen and Pavel finds a morganite dike. We dig at it for about half an hour and the experience is unforgettable.

11) rubellite from depth of 46 m from Muiane aditOne of the strongest impressions surely was the visit of the biggest and most famous pegmatite body Muiane. In comparison with the size of our pegmatites Muiane is gigantic - the verified thickness of the lens-shaped body is 400 m and the length is over 1 km. With regard to the subtropical climate the feldspar decomposed and kaolin was formed, its deposits visible for miles thanks to its bright white colour. In the centre of the pegmatite there is a several dozen meters thick quartz core, 12) Pavel and Luboš at the lookout from the kaolin mountain in Muianemade up of grey block quartz, around there is a highly developed lithium metasomatism (original feldspar pushed out by albite and lepidolite), which binds all interesting minerals and often contains cavities (with secondary kaolin filling) and that is what we concentrated on. (photo no. 11, photo no. 12) It is common that one finds druses of light violet flakes of lepidolite, crystals of milky quartz and fragments of crystals of coloured tourmalines (mainly rubellite), more rarely crystals of microlite, tantalum niobates, morganite and decomposed spodumen, whose gem varieties (kunzite, hidenite) can be found a few dozen meters deeper in the zone of lesser kaolinization.

13) Pegmatite - Naipa - interesting metasomatic positionThe situation is similar at the nearby, 6 km distant deposit Naipa, where more complex, differentiated pegmatite bodies of lens and dike shapes are found. The dikes are less thick (around 10 m), there is no lithium mica and the metasomatic layer is generally less developed. But the quartz-feldspar core remains with its big blocks of greyish quartz and potassium feldspar, in the vicinity of which cavities occur frequently, filled with large quartz crystals, 14) Picked and dug out specimens from the locality Naipa - verdelites ingrown cleavelandite a tourmaline, often ingrown into quartz crystals. The size of quartz crystals often reaches 50 cm, the bottom greyish parts pass into citrine top endings. (photo no. 13, photo no. 14, photo no. 15)
Large lens-shaped bodies typically have a strongly developed metasomatic zone with lepidolite, coloured tourmalines, kaolinized spodumen, beryls and Ta-Nb minerals. Spodumen grows ingrown crystals of over 1 m, unfortunately in most cases fully kaolinized. Nonetheless sometimes there are relicts of unmetamorphosed parts, often of gem quality (kunzite).


Previous page     Page 2/3    Story continued