Brhino
02-24-2010, 12:16 AM
a few years ago, I found a Petoskey stone on the shore of Lake Huron. Petoskey stones are the state stones of Michigan. If you've never heard of them before, here's what Wikipedia says:
A Petoskey stone is a rock and a fossil, often pebble-shaped, that is composed of a fossilized coral, Hexagonaria percarinata. The stones were formed as a result of glaciation, in which sheets of ice plucked stones from the bedrock, grinding off their rough edges and depositing them in the northwestern portion of Michigan's lower peninsula.
Petoskey stones are found in the Gravel Point Formation of the Traverse Group. They are fragments of a coral reef that was originally deposited during the Devonian period, about 350 million years ago. When dry, the stone resembles ordinary limestone but when wet or polished using lapidary techniques, the distinctive mottled pattern of the six-sided coral fossils emerges. It is sometimes made into decorative objects. Other forms of fossilized coral are also found in the same location.
As the article says, they don't look very interesting when dry, so mine has been living quiet ingloriously in a water-filled pickle jar for a number of years since I found it. Today it occurred to me that it would be much more appropriately positioned inside my fish tank. sort of a no-brainer, really. However, I am mindful that not all stones are suitable for the tank, as some will leach out toxins, or throw off the chemistry of the water. So... how 'bout it, folks? Is a 350 million year old piece of fossilized coral suitable for a freshwater tank?
A Petoskey stone is a rock and a fossil, often pebble-shaped, that is composed of a fossilized coral, Hexagonaria percarinata. The stones were formed as a result of glaciation, in which sheets of ice plucked stones from the bedrock, grinding off their rough edges and depositing them in the northwestern portion of Michigan's lower peninsula.
Petoskey stones are found in the Gravel Point Formation of the Traverse Group. They are fragments of a coral reef that was originally deposited during the Devonian period, about 350 million years ago. When dry, the stone resembles ordinary limestone but when wet or polished using lapidary techniques, the distinctive mottled pattern of the six-sided coral fossils emerges. It is sometimes made into decorative objects. Other forms of fossilized coral are also found in the same location.
As the article says, they don't look very interesting when dry, so mine has been living quiet ingloriously in a water-filled pickle jar for a number of years since I found it. Today it occurred to me that it would be much more appropriately positioned inside my fish tank. sort of a no-brainer, really. However, I am mindful that not all stones are suitable for the tank, as some will leach out toxins, or throw off the chemistry of the water. So... how 'bout it, folks? Is a 350 million year old piece of fossilized coral suitable for a freshwater tank?