Japanese Chrysanthemum Flower Stones
日本の菊花石 Part 1.
Chrysanthemum flower stones have been collected and appreciated for their beauty and striking resemblance to their real life namesake autumn flowers. It was not until the early Showa era– the 1930s—that these stones became popular in Japan. The fact that the Imperial crest was a sixteen-petal chrysanthemum flower and that several extraordinary chrysanthemum flower stones were presented to the Imperial Household in the 1930s helped promote these stones.
These stones were first formed approximately 250 million years ago on the shallow sea floor, and later uplifted, and then subject to various tectonic actions that resulted in their current presence in veins high in the mountains. The stones naturally occur in several forms—those that have been tumbled and washed in high mountain rivers, and those removed from the earth via small-scale mining operations. These river-washed stones are known as kawazure seki and are not often seen. Mining produces numerous small- to medium-sized boulders that have to be worked to expose the flower-like mineral deposits, usually formed of calcite. Cutting and mechanically removing the matrix stone and then polishing the surface to highlight the “flowers” is the most prevalent type of manipulating chrysanthemum flower stones in Japan, perhaps as much as 80% of those in collections.
Occasionally, three-dimensional mineral formations form in air or soft mud pockets or cracks in the matrix rock when it was formed. Good examples of these are highly prized in Japan among collectors. These striking, typically rugged formations clearly illustrated the three dimensional nature of these fascinating stones. This type of stone is known in Japan as a saba-ishi if the crystals are present and as a nuke sabe ishi if the mineral crystals have been lost and only a cast of the flower remains.
Most stone enthusiasts are familiar with the beautiful and often colorful chrysanthemum flower stones that originate from one of several mines in Neo Valley, high above the city of Gifu. Stones from these mines were collected in the 1930s but more so after the recovery from World War II when they were cut and polished in large numbers. The colors in these stones come from mineral impurities such as iron oxides formed with and without the presence of oxygen, copper oxides, cobalt, and other minerals. Mining for chrysanthemum flower stones reached a peak between 1960 and the 1980s when there were over a dozen active mines. Today there is only one active mine. Neo Valley chrysanthemum flower stones are the most popular among collectors of the different types in Japan.
The value of a polished chrysanthemum flower stones depends upon several factors—shape of the stone, distribution of the “flowers”, color, and especially how well individual “flowers” are defined. Flowers with a clear center and radiating “petals” are the finest. Stones with a good contrast between the background matrix stone and the flower-like mineral formations, and those with one or more colors are more highly valued.
In addition to those found in Neo Valley, several other locations have produced nice chrysanthemum flower stones with specific characters that can be used to distinguish them.
(to be continued next month)