Petrified wood: properties, application

Petrified wood is a material formed from trees that grew in the past geological epochs. Such "rarities" can tell a lot about. Given the age of the trees, they can be used to trace the evolution of tree species of a certain species, to learn about the time of their growth and the climate of past centuries.

How does the fossilizing process take place?

In natural conditions, wood residues decay, they are processed by microorganisms. This is the case in the case of free air access. But in some cases the dead tree does not completely collapse. This happens when it is buried under sediments (volcanic ash, landslides, collapses, glacial moraine, etc.), which prevent the entry of oxygen. As a result, the wood does not deteriorate, but with time it becomes petrified by replacing organic substances with minerals. The physical properties of the tree completely change, and it turns into a very dense and durable material.

In most cases, the organic tissue of the tree is replaced by silica minerals (silicified wood). Mostly it is opal, chalcedony or quartz. Such fossils retain the anatomical structure of the wood. More rarely you can find a so-called marbled tree, the main substitute minerals in which are dolomite, calcite or siderite. In addition, substitute elements can be gypsum, barite, gagat, etc. More than 60 minerals are known to take part in the formation of wood fossils.

The main properties of the petrified tree

The mineral is characterized by a glass or wax gloss, a wrinkled fracture, a lack of cleavage. The hardness of petrified wood, depending on the replacing minerals, ranges from 4 to 6 on the Mohs scale. On one slice, you can find areas that are largely different in structure and color.

Due to the presence of impurities in sediments or water, fossilized material can have a wide variety of colors. So, carbon gives the tree a black color; Iron oxide - red, yellow or brown; Copper, chrome and cobalt - green or blue; Manganese - orange or pink; Manganese oxide - black or yellow.

Among the fossilized trees, coniferous and deciduous species can be found. Coniferous fossils include inclusions of amber.

Textural varieties

Wood that has been petrified can have a different texture. The reason for this is a lot of factors. Let us consider in more detail the existing textural varieties of the petrified tree, and also due to what they were formed.

Homogeneous fossils

Include varieties, which are characterized by a practically homogeneous structure with different colors. The stone has an indistinct zoning, which is due not to the difference between the coloration of the annual rings, but only to the presence of lines that limit them. The most famous representative of this group of fossils is the so-called opal tree, which is very light in color (it can be practically white) and usually retains its primary structure.

Petrified wood: lens texture

This texture develops in the process of filling large cells and pores with chalcedony, opal, and iron hydroxides. Lenses are characterized by a linear orientation. In a number of cases, it is emphasized by iron hydroxides developing in the same directions.

Spotted tree

It is the most common type of fossilized tree. Characterized by an opal-chalcedony composition with a significant admixture of iron hydroxides. In this case, the ratio of these three components is variable, which explains the uneven patchy color and texture of the mineral. Sometimes the spotting is caused by the relics of the tree, which replaces chalcedony, preserving the shape of the cells against the background of opaline mass. Such a stone is inherent in coloration, including various shades of brown.

Concentric-zoned petrified wood

The material is characterized by the alternation of opal or opal-chalcedony concentric bands of different colors. At the same time, they emphasize the drawing of the annual tree rings in the cross section. The longitudinal section has a linear banded texture, which is quite clearly expressed.

Gamut-like petrification

This petrified tree has a carbon-opal or carbonaceous-carbonate composition. Lines of annual rings are clearly expressed and form a concentric (sometimes wavy-concentric) pattern. By decorative qualities, the black petrified tree is compared with black jade or a diver.

Where do fossils of trees

The most frequently fossilized trees occur in areas where volcanic eruptions have occurred. The most famous location for the discovery of this unique material is the so-called "Petrified Forest", located in Arizona and one of the national parks of the United States (since 1962). The length of petrified barrels reaches 65 m, diameter - 3 m.

There are also a number of other deposits of petrified wood that are located in different parts of the world. The most famous and significant fossilized forests are in Argentina, Brazil, Belgium, Greece, Canada, India, New Zealand, Russia, Ukraine, Czech Republic, Georgia, Armenia, etc. Many territories are national parks or natural monuments.

Applications of petrified wood

Petrified wood is a stone used since ancient times as a raw material for making jewelry. The demand for them remains high at the present time. This decorative stone is very easy to process. It is perfectly cut, polished and polished, resulting in a kind of glass shine. When processing does not lose its wood texture.

Species of the petrified tree, which have a fine contrast pattern, are used to make inserts and small jewelry such as, for example, beads, bracelets, etc. Particularly valuable is a decorative stone with distinct lines of annual rings. When making jewelry, such samples are often combined with precious metals, other stones and glass.

Also, the petrified tree is used in the production of various souvenirs and interior decoration items. It can be pens, ashtrays, vases, caskets, shelves, countertops and much more. For the manufacture of such products, a material with a less pronounced zonation and having a patchy-banded or coarse-grained pattern is often used. The stone is highly valued by collectors, given that the age of trees is estimated to be millions of years.

It should be noted that the fossilized tree is considered a material with special healing properties. It helps a person cope with stress and fight stress, increases the vital forces of the body, protects against infectious diseases and injuries. According to folk medicine, a die made of a petrified tree can alleviate pain. To do this, simply attach it to the sore spot. In Mongolian medicine, since ancient times, with arthritis and similar diseases, a petrified tree (in the form of plates) is applied to the joints from the Gobi Desert.