Wood Stone
Wood stone is also known as petrified wood or silicified wood. This stone is more reminiscent of a piece of wood than a mineral . This is because the minerals did not take on their actual form, but that of the wood ( pseudomorphism ).
Petrified wood results from the washing out of the organic components covered by sediment and the replacement by minerals, mostly chalcedony or jasper , but rarely also opal ( wood opal ). The finer the surrounding sediments are during silicification, the more details can still be seen in the fossil wood after completion . Sometimes even exposed passages and caves of living beings can be recognized on polished panes of wooden stone, which lived in this tree during the late Triassic about 230 million years ago (see picture opposite).
Due to the inclusion of chemical iron compounds during the petrification phase, petrified woods of the araucaria are often particularly colorful.
Well-known deposits for wood stone include the petrified forest between Holbrook and Navajo in the Petrified Forest National Park with araucaria tree trunks up to 65 m long and 3 m thick.
Silicified wooden fossils are often processed into various handicraft objects and decorative pieces, but also into pieces of jewelry , due to their aesthetic structure and color .
Web links
Individual evidence
- ↑ Ludwig August Emmerling: Textbook of Mineralogy . tape 1 , first part. Heyer, Giessen 1799, p. 258–262 ( limited preview in Google Book Search [accessed August 18, 2019]).
- ^ Walter Schumann: Precious stones and gemstones. All kinds and varieties. 1900 unique pieces . 16th, revised edition. BLV Verlag, Munich 2014, ISBN 978-3-8354-1171-5 , pp. 164 .
- ↑ Andreas Landmann: Adventure Mineralogy: Crystals and Minerals - Determination and Origin . Springer Spectrum, Berlin, Heidelberg 2013, ISBN 978-3-642-37743-3 , pp. 38 , doi : 10.1007 / 978-3-642-37743-3 ( limited preview in Google Book Search [accessed August 18, 2019]).