Sado Island Akadama Stones
by Tom Elias
Dark reddish scenic landscape or hut-shaped akadama stones are seen in most modern, major suiseki exhibitions in Japan. Typically, these stones are darker in color, with a subdued reddish color. They express a more subtle and refined beauty than bright red-colored stones. The use of akadama from Sado Island is old, dating back to the late 1500s. These stones have been used for making jewelry, outdoor landscape pieces, and as viewing stones.
Sado is the sixth largest island in the Japanese archipelago and lies close to the city of Niigata on the west coast of Japan. It has two parallel relatively low mountains with a central plain between the two ranges. Sado became famous after the discovery of gold there in 1601 and the discovery of silver deposits in 1546, and its subsequent mining activities. Sado was also known as the place where people were exiled. Eventually, agriculture and fishing became its most stable industry.
Large pieces of akadama were hauled by boat to nearby Niigata for use as landscape stones. Many of these pieces were taken to other regions of Japan, such as the well-known Kiyosumi Garden built by Iwasaki Yataro in Tokyo between 1878 and 1885. This picturesque stroll garden features numerous types of native landscape stones that have been used to create dry landscape scenes around a large pond. A stroll garden typically has a meandering path that leads visitors from one scene or highlight to another and offers pleasing views from different vantage points.
The Sado Island red stones have been referred to in reference guides as red chert or jasper. Chert is a type of sedimentary stone composed of silica dioxide (quartz) with microcrystalline or cryptocrystalline structure. The reddish colors are derived from iron oxide impurities. Brighter reds typically result when iron oxides are deposited with little or no oxygen present, while brown and rusty color deposits result when higher levels of oxygen are present. Jasper, a generic name, is often used to describe any microcrystalline quartz that is brown, red, orange, green, or yellow. Sado Island akadama stone should more accurately be called red chert.
There are four main collecting localities on Sado Island according to Tatewaki Takahiko, a Sado Island akadama specialist in Niigata. One location, Akadama, produces mainly red chert; Hamochi produces five-color stones; Iwayaguchi produces red stones with whitish inclusions; and the Ogura site whose supply was exhausted by 1975. Many of the stones were dug from rice fields. These stones were blocky in shape and often with sharp edges and were worked by removing small pieces with a chisel to improve the shape. According to Tatewaki most of the nice scenic landscape or hut-shaped stones sold by suiseki dealers in Japan have been worked to improve their appearance. The darker red and more subtle colored stones are favored by Suiseki collectors. Some Sado Island akadama stones are shaped and polished to make indoor decorative items and biseki.
Multi-colored stones and ones with significant white color impurities are too colorful to meet the traditional requirements for suiseki, and are thus best considered as biseki.