Report visit Zhuji, China
Fig.1: The town Zhuji
Many other gemmologists and pearl dealers have been there before, perhaps for them this report will bring none or little news.
Zhuji is a small town with about 60.000 citizen, 50 km south of Hanzhou and 170 km southwest of Sjanghai, fig.2. It is situated in a long valley. Although a pearl centre, the city is not surrounded by large lakes for the pearl farming. But just a few kilometers outside the city you can find the large offices of the bigger pearl companies, fig.3. The plans are to make that an area solely for the pearl business with offices, hotels and restaurants, fig.4.
There are small lakes and ponds around Zhuji where pearls are cultivated, but the major production lakes are hundreds of kilometers more to the west. We have not visited those lakes.
Fig.2: Map of Zhuji
The small lakes around Zhuji in which pearls are cultivated are situated between houses, farmland and factories, fig.5. Those lakes are often between 1.5 and 3 meter deep and often as small as 50 x 50 meter to a 100 x 150 meter (estimated). Some of those were rice fields before.
It seems that the big production lakes in the west are hundreds of meters to kilometers across.
Fig.3: Office of
Grace Pearl Co, Zhuji
Fig.4: Plan of
the pearl centre
Fig.5: Production lake
Fig.6: Net with mussels
The mussels hang in pairs in a small net, fig.6, hanging on a line and are kept afloat by empty plastic bottles, fig.7. The nets are hanging only 20 to 30 cm below the surface and about 50 cm from each other.
The mussels which were used are the Hyriopsis cumingii, or a crossbreed, or a genetic manipilated species. The maximum size of the shell is 20 x 15 cm. The pearls these mussels produce are coloured: light pink, greyish blue, yellowish orange, purple and all colours in between. The possible colours of the mother of pearl are clearly seen on the inside of the shell.There were few white pearls, they are bleached light coloured pearls. Most of the white freshwater pearls are supposed to be produced in the Christaria plicata which I have not seen around Zhuji. I suspect those are cultivated in another part of China.
Between September and February most of the harvesting is done. The mussels are taken from the water and transported to an area where workers process them, fig.8. What we noticed is that the workers were older people. The first row of workers opens the mussel with a big knife or kind of hatchet, fig.9. To prevent cutting themselfs from the mussel one hand is protected by a glove.
Fig.7: Pearl farm
Fig.8: Processing square
Fig.9: Opening of the shells
Fig.10: Opened shell and a
basket with mantles
After opening the mussel, fig.10, the mantle on both sides is ripped away and put in a basket, fig.11a + 11b. The shell with the body is thrown backwards. In a second line workers remove the body and throw the empty shall backwards. Also blisters or pearls which are stuck on the shell are roughly removed by a hammer. The bodies are collected and put out to dry. They are used for fodder at fishfarms. The empty shells are collected and put on waste dumps, fig.12, you see them along the roads here and there. Nobody knows what to do with it. If anybody has a good idea they can become rich !
Fig.11a: Mantle
with pearls
Fig.11b: Mantle
with pearls
Fig.12: Removal of
empty shells
Fig.13: Mantle centrifuge
The mantles are collected and put in some kind of centrifuge, it is not really clear what happens, but I suspect that the mantle tissue desintergrate somehow and the pearls in the mantle come free, fig.13. From the resulting slurry the pearls are separated, fig.14, and collected, fig.15 + 15a. The remains of the slurry is waste. The pearls are then put in baskets and transported to the factory, fig.16.
In the factory the pearls are cleaned and sieved for the different sizes, fig.17.
Fig.14: Cleaning
of the pearls
Fig.15a: Collection
of pearls
Fig.16: Baskets
filled with pearls
Fig.17: Sieving
for size
It was not clear if the pearls are polished before or after grading, but most likely before. The polishing is done by round vertical, fig.18, and horizontal tumblers, fig.19, the latter uses hexagonal drums and are bigger. The polishing is from 30 to 60 minutes. The pearls are mixed with small pieces (2-3 mm) of dried corn, fig.20. Any addition of polishing powder or chemicals we have not seen, but it is likely. After the polishing the pearls are cleaned and dried, fig.21.
Fig.18: Polishing
in vertical drums
Fig.19: Polishing
in horizontal drums
Fig.20: Seperation
of the pearls
Fig.21: Polished pearls
The next step in the process is grading of the pearls by hand, fig.22.
The grading is done by young people, most of them girls aged (we think) around 18 to 20. In the grading room was a good atmosphere, hardly any talking, with everybody very concentrated at work, fig.23.
Depending on size, shape, lustre and condition of the surface the pearls are drilled and used for strands or hanging jewelry, fig.24 + 25. Only the best quality is not drilled but sold loose. For special orders from clients pearls are seperated and threaded to strands, fig.26.
Fig.22: Sorting hall
Fig.23: Sorting
Fig.24: Drilling
Fig.25: Drilling Machine
It seems that factories are doing their best to keep their workforce happy. Which means good payment, good food and good lodging. We saw the kitchen and it looked super-clean and modern.
Our host told us that the company was building a new flat for the workers to give them a better housing. If an employee uses the company's lodgings they have their own room. On the upper floor of the office building there were all kind of apparatus for relaxing. The companies are putting a lot of effort in keeping experienced workers, this is not only in the jewellery business it seems. With the fast growing economy the industry needs reliable people.
Fig.26: Stringing strands
The area around Zhuji is one of the richest in China, we were told. Walking through the city for hours we certainly did not have the idea we were in a poor or backward country. In Zhuji there is even a coffee-shop ! (No, not a Dutch coffeeshop, a real one where they made and pour good coffee. But European prices, which means a fortune for Chinese.)
Many people think that buying at the source is the cheapest. This is not so as many gem dealers know. It is the same in Zhuji. I could understand that real big pearl dealers could buy at the company's head-office, but nearly all production goes to their office in Hong Kong. There is none, or hardly any price difference between Zhuji and Hong Kong.
Fig.27: Treatment
apparatus
In the laboratory of the company we were showed a few rows of closed cilinders, they looked like pressure containers, fig.27 + 28. In this vessels pearls were bleached and dyed. In the lab were no workers and there was not so much to be seen. For the bleaching and dying processes the pearls have to stay in the containers for months, perhaps on a higher temperature. We did not see any results.
In the grading 'hall' I saw that one of the graders was working with nucleated pearls, fig.29. It was clear that the experiments were not going very well. The nucleated freshwater pearls I have seen till now all had a so-called 'wing', fig.30. This originates from the way nucleated freswater pearls are produced. After the first operation with a piece of mantle tissue a pearl is formed. This pearl is carefully removed and a nucleus implanted instead. Then the second pearl is formed. It takes about three to five years to form a 8 mm pearl. If this pearl is changed for a nucleus then in one to two years a 10 or 11 mm pearl is made. There seem to be some nice shaped good quality nucleated freshwater pearls on the market, although not many. But it is only a matter of years till the pearls producers have overcome the failures and can make nice round nucleated pearls up to 15 mm.
Fig.28: Treatment
apparatus with chemicals
Fig.29: Pearls with nucleus
Fig.30: Nucleated pearls
Fig.31: Backstreet shop
In Zhuji a 'Pearl centre' has been made where all companies in the pearl trade can have a shop. It looked more like a pearl market. Most of the buyers were Chinese shop owners from other parts of China. We saw no other foreigners. The sellers did not bother us at all, but were friendly without pushing.
The average quality was low to medium and the prices very low. Spending a few hours there we did see some special pearls. I bought a very good reddish lavendel coloured freshwater pearl, dome shaped, of 14,0 x 13,1 mm, a huge pearl for its kind ! Also real tiny seed pearls 1 - 2 mm on strands, some really very fine quality, reasonable priced, but not cheap.
Looking for food we discovered in the street behind the centre many small workshops dealing and working in pearls. In one of those shops we bought cards with flat pearls, amazing cheap : 49 pieces for US$ 7.- ! Good for research and cheap jewelry.
Economics
Fig.32: Pearlfarm at
Busuango Philippines
The pearl cultivating in China is in sharp contrast to the cultivating of marine pearls. Pearl farms of Southsea and Tahiti pearls in Australia, Indonesia, Philippines, fig.32, and Polynesia are all located in remote areas where there is very limited human activity and very pure sea-water. Every kind of pollution can have desastrous consequences for the quality of the pearls or causes deseases or mortality of the oysters. To prevent growth of algea and attacks by parasites divers have to check the oysters every few weeks, fig.33. Every 6 or 8 weeks oysters have to be pulled from the water to be cleaned of any growth upon the shells, fig.34.
This all means that for cultivating marine pearls you require a lot of labour and because those people do not live in the area, they need lodging, food and transportation, fig.35. In Indonesia and the Philippines a few good armed guardsmen are not a luxury, they are a necessity, fig.36. Also all the necessary materials have to be brought in from far away, sometimes by planes. In some parts of Australia ships with divers and operators are at sea for weeks. Last but not least, every oyster produces only one pearl !
Fig.33: pearlfarming near
Phuket Thailand
The cost of operating a marine pearl farm are staggering. Boats, thick lines (strong enough to withstand a typhoon), big bouy's, rafts, and so on and so on. Not to forget that a nucleus of 10 mm cost about 30 to 50 dollarcent. Imaging you need a 50.000, which is a normal amount to use in a year for a farm, that is US$ 15 - 25.000! Marine pearl farming is very cost- and labor intensive, has a high risc and often low profits.
Fig.34: Cleaning the
oysters Busuanga
Fig.35: Transportation of
goods Busuanga
Fig.36: Busuanga
watchtower
In China the situation is different. The owner of the farm will have a look once a week (after his work hours) to see if everything is ok. With closed small lakes and ponds the water should be refreshed once a year. There are no problems of cleaning, storms or typhoons, a work force from far away, kitchens, barracks, bouys, kilometers of thick lines, boats and nuclei.
If a farmer, or any owner of pond has some money, he can buy a few 10.000 mussels and have them operated. The small nets contain two mussels and are kept floating on (probably) used plastic bottles. A small boat is nicer, although it seems that you can walk in most of the small ponds.
After three to five years the owner can harvest the pearls. He could get 15 to 20 pearls per mussel. Which means making a strand per two mussels. Poor guys with the marine pearls, they need 33 to 40 oysters to make a strand.
This all means that marine cultivated pearls have to be more expensive than the Chinese freshwater cultivated pearls. The Japanese freshwater cultivated pearl business is a different story.
Because most of the marine pearl farmers are experts in cultivation the result is that 50% of the cultivated pearls are of commercial quality or better. This is certainly not the case with the Chinese production. Most of the cultivated pearls are of low quality, hardly good enough for export to countries with a low economy. But everything is sold somehow. Because of the the 'easy' and cheap way of cultivating and the huge area of lakes the Chinese farmers can produce 800 to 900 ton of pearls every year. Considering the amount of cultivated pearls it is very well possible that the Chinese producers have to dump quantities to prevent holding too much stock.
Therefore strands of low to medium quality freshwater pearls can be found for impossible low prices.
But once you start looking for good to high quality pearls it becomes much harder to find those and the price goes up fast. Dealing with good to high quality freshwater pearls it is my guess that perhaps 0,01 % or less is of high quality, which means round or near-round, good colour, high lustre, none or few spots and a diameter above 8 mm. The best white or coloured pearls of 9,0 to 9,5 mm cost about US30.-/piece in Hong Kong. Sizes above 12 mm are nearly not available now, but that is changing. It is expected that in a few years time white pearls of good quality will be up to 15 mm. Strands of white pearls 12 to13 mm are now half the price of the same quality and size in South Sea pearls. Although there is still resistence in the trade against freswater pearls, because of those cheap, abundant strands, the good qualities and bigger sizes are becoming more popular.
In the sizes between 6 and 8,5 mm the white freshwaters have replaced the akoya's. The akoya business is finished, only viable for the real supporter. It is a fact that akoya pearls can have the highest lustre, the freshwater pearls can be good, but not that good. However, to find a good quality strand cultivated akoya pearls with a thick layer mother of pearl is difficult. Most have thin layers (about 0,4 mm) which causes well-known troubles. A freshwater pearl without a nucleus is in fact the closest you can get to the natural pearl, if it has a good lustre and is less than half the price of an akoya than it is clear what the consumer decides. The same counts for the cultivated South Sea pearls up to 13 mm now and 15 mm in the near future.
Every year the Chinese cultivated freshwater pearls are becoming better and bigger. In my opinion akoya production is doomed, only the larger sizes and top qualities will be salable. The South Sea production will have a hard time in the future for white pearls with sizes below 15 mm.
The Tahiti's and golden pearls have nothing to fear from the untreated cultivated freshwaters pearls.
Peter Groenenboom FGA, FGG
AEL-Arnhem, Netherlands
The author would like to thank the following people:
•the management of Grace Pearl for their fantastic hospitality and information,
•dear Emma from their HK office for all her efforts,
•Ciska and Miriam for the company,
•Edward Johnson for the editing of this article.