木化玉 - mauriceling/mauriceling.github.io GitHub Wiki

上古之树已明终，
沉息阴土木不朽。
千年时光硅踢碳，
从此石化带木文。
分又水浸矿填色，
铜而生绿铁而红。
又有地压千万年，
温度恰好石英晶。
低温不凝高而溶，
巧夺地理石化玉。
最早树玉三亿年，
最迟六千五百万。
惜之此玉来不易，
颗颗天时地理合。
— 18/12/17.

Commentary: Nothing amazed me more than the creation of Tree jade, which started as a tree. When this tree died, it got covered with mud and prevented the rotting process. If the conditions were right, the tree got fossilized into a stone, known as Petrified wood. This process can take as short as a few thousand years. If the conditions were right, the quartz in Petrified wood can be slightly melted and re-crystalized under the heat and pressure of the earth, turning the Petrified wood into chalcedony, which is then known as Tree jade. This process takes millions of years and the conditions must be just right – too hot and the structures will be lost; too cold and melting will not occur. Tree jade are from trees in Cretaceous period (65 million years ago) to as old as Carboniferous period (3 billion years ago). Hence, each piece is a treasure.