By Neelamanee De Silva (Consultant Gemmologist)
Reproduced with kind permission from the National Gem and Jewellery Authority
A miner at Opanayake has told his friends at a funeral that he had witnessed some people collecting gunny bags full of some stones which appeared to be greenish blue glass (Ground glass) from a recently excavated quartz quarry at Akerella plantation, and that is where the rumor began.
Four years ago at a place in the Ratnapura valley called Akerella group of platations of rubber and tea, the owners got a license to excavate white and rose quartz for the nearby ceramic factory at Balangoda.
The Bedrock of the area is coarse grained pegmatite and consists of huge boulders of white and rose quartz (Clear and clean) which is one of the primary raw materials of used for the production of ceramics. Labourers who excavated the rock were not very familiar with gemstones but in the neighbourhood there were many gem miners . When the aquamarine deposit was exposed to the surface none of them were aware of the real value of it. Some people who knew the value have been collecting it secrectly without their knowledge. But it did not remain as a secret for long and the merchants of the area have got samples tested and found out the value.
The usual practice of haphazard mining started immediately after it was revealed and not only the miners of the area but many prople from distant places have gathered to try their luck.
A dispute between the miners and the police led to the death of a young miner as well.
I visited the mine in november 2006 with a student of mine who is the public health inspector of the area (Mr Manjula Wijesundara) and through him I met many pioneers in mining who were engaged in the excavation of the deposit . They were also well aware of the subsequent incidents that followed in observing the geology of the area. It was found that part of the hill was covered with the rubber plantation where the excavations have taken place and according to the miners the aquamarine vein was not fully excavated and it runs deep into the plantation area as well . Since the owners have restricted the area for further mining and have taken an injunction therefore the miners cannot proceed any further.
Most of the miners we have met have had chances of excavating good quality aquamarine . Most of the deposit was in crystal form , there were large crystals as well as smaller ones and some are matured and some were of very good quality and sizes ranging from 3 cm to 7 feet in length. It was primarily an undisturbed formation according to their description. We managed to collect some smaller samples from the area and a big matured partly damaged crystala well. The old watchman of the plantation had a small collection which he had collected and which cost us only Rs 100. He was also very happy to part with at that price. There were some very good small crystals and good coloured aquamarine in the lot.
The figures above shows the rough pieces of aquamarine found and some cut and polished aquamarine of good quality from the area.
The colours of the stone vary from greenish blue to sky blue and pale blue. Highly Dichroic , very clean spicemens were also found in large sizes .Perfect crystals with symmetrical hexagonal formation was found in different lengths. But large crystals were flawed and full of salt like minute crystals and long hollow tubes.
The area is nearly four kilometers from the Colombo Badulla main road and the byroad leading to the estate is heavily damaged . It is a road with a deep slope on the right side and the deposit on a steep slope of the hill that could lead to a landslide any moment due to the frequent heavy rains. The haphazard mining and the subsequent exposure of the huge unprotected boulders along the steep slope is already a danger to the surrounding low lying areas.
According to what I have gathered from the stratigraphy of the area , the owners of the plantation have taken a wise decision of terminating the excavations.
There is the possibility of the boulders as well as part of the hill rock to slide during the rainy season as the mine pits are not covered and there will be a possible leakage of water through these pits to the interior of the hill which could lead to the formation of a colloidal debris , and might collapse along with the huge unstable boulders on the surface.
Precautions must be taken before allowing people to perform mining activities . It is advisable that it should be done under strict observation of the authorities and mining specialists.