Go Stones Guide
Go playing stones can be made from many types of material and come in varying sizes. The most common stone shape is double convex. In China, however, players prefer to play with single-convex stones because of the louder 'snap' the flat side makes when played on the board. They are also handy for flipping over when reviewing games and playing out variations. A standard set of Go stones has 181 black stones and 180 white. Black has an extra stone because it plays the first move. The total of 361 stones is enough to cover every intersection on the board. Of course, you can still play a complete game with fewer stones so don't worry if you end up missing a few.
Yunzi is the national standard for professional tournaments in China. Yunzi has a long history dating back to the Tang Dynasty (618 A.D. – 907 A.D.). The stone has a property which absorbs moisture from one's fingertips without picking up dirt, and a resonant quality that gives it a pleasing sound as it lands on the board. Yunzi has a nice heft to it and is heavier than shell and slate stones of equal size. The white stones have an opaque milky eggshell luster. The traditional type of Yunzi, known as 'Old Yunzi', has a stronger hint of yellow in its white. Black Yunzi has a similar luster but when held up to the light it produces a bluish green halo along the rim.
Really old Yunzi from the Ming Dynasty
The actual composition of Yunzi is a tightly guarded secret known only to a select few in Yunnan Province, China. According to legend, the secret for making Yunzi stones was first revealed during the Tang Dynasty, when Taoist master Lu Dongbin, one of the "Eight Immortals" of Chinese myth, was traveling through the village of Yongchang in Baoshan County. He came upon a poor peasant who had devoted his life to taking care of his aged mother. Lu Dongbin taught the young man to make Yunzi stones out of agate and amber, materials which were plentiful in Yongchang. The young man soon became rich and "Yongzi" stones, as they were then called, became famous all over China.
After flourishing for hundreds of years and being the favorite of emperors, scholars, and monks, Yunzi stones production in Yongchang came to a halt when China was plagued by the civil war in the early 20th Century.
The secret to making Yunzi stones might have been lost forever if it weren't for Zhou Enlai, who took a trip to Baoshan County in the 1960's and charged the Yunnan Sports Commission with figuring out the secret formula for Yunzi stones. Old stones were available, as were old quarries for raw materials. But it wasn't until many years and hundreds of scientific experiments before a stone was produced that China's top Go players agreed was equal or superior to the old "Yongzi" stones.
Yunzi stones can only, by Chinese law, be produced by the state-run Yunzi company. The formula is still secret, although it's likely that the main ingredients are ground Yunnan mountain stones and agate.
How to Care for your Yunzi Stones
The black stones arrive with a little white powder on them. This is normal with new stones. Take the following steps to bring out the full luster:
1. Rinse the stones clean under water and lay them out on a towel to dry.
2. Place the stones in a plastic bag with a few drops of colorless oil and mix them around until the stones are all coated. Sewing machine oil is suitable, avoid cooking oils.
3. Wipe the stones clean of excessive oil. Remember, the stones absorb moisture and oil from your fingers so the more you play, the nicer they will look!
Produced in Hyuga city, Japan, shell & slate are some of the most coveted types of stones out there in the Go world. While the game of go was introduced to Japan during the Taiho era (701 A.D. – 703 A.D., it wasn't until the 17th century that the Japanese began to make stones out of clam shells. Initially made in Hitachi and Kuwana, it was during the middle of the Meiji era (1868 – 1912) that the Japanese discovered using Hyuga clam shells for stones. The clams from Okuragahama beach in Hyuga had much thicker shells and finer grains, thus cementing the area's reputation as the home for shell and slate stones.
Do Not Eat
Hyuga city is now the only place in Japan where shell & slate stones are made. However, clam shells in Hyuga are nearly extinct, and while stones produced in Hyuga are still crafted with perfected traditional techniques, almost all of the shells are imported and harvested from off the coast of Baja California, Mexico. One can still find stones made from Hyuga shells but will have to expect to pay a premium of several times the price of normal shell & slate.
The stones come in different grades rated based on their coloration and line patterns. From lowest to highest the stones are rated as Standard (Jitsuyo), Moon (Tsuki) and Snow (Yuki). Snow grade shell stones are the whitest with the fine straight lines running across the top of the stone. Tuski stone lines are broader and curve across. Jitsuyo stones have more irregular and coarser lines with slight discoloration.
How to care for your shell & slate stones
You can clean your shell stones by simply wiping them off with a 100% cotton cloth. If the stones need more serious cleaning, mix them with a fresh egg and wash the stones in the mixture. Clean and rinse them in tepid water for a few minutes and let them dry overnight. Soap is also safe to use for cleaning. Do not use oil on shell stones!
The most common material used for stones. Glass stones are inexpensive yet have a very nice heft and feel to them. They also create a nice snapping sound when played on the board.
Another common and inexpensive material used for stones. Ceramic stones have a matte finish that has a more natural aesthetic appeal in contrast to the more glossy glass stones. These stones are very durable and don't chip easily.
Now for sizes. Here are some charts for making heads or tails out of Go stone sizing standards.
Double Convex Sizes
Single Convex Sizes
Chinese weiqi academy standard size is 21.5mm, 8.8, Old Yunzi. If you're looking for single convex, make sure you have the right size to fit your board!
||6 (Extra Large)