Scientists are curious about rocks that can grow and move. This stone originates from Romania and is known as a trovant.
This uniqueness made ordinary people think that Trovant came from outer space. The results of the study stated that trovant really came from Earth and was naturally formed by geological processes.
Quoted from the Daily Mail, the life of these rocks starts as gravel and grows about 2 cm per 1,000 years. Trovant rock contains a unique mineral structure that mimics plant and mammal life.
The strange round stones seemed to grow in much the same way as plant tissue, and they 'give birth' to new stones like animals.
Trovant stones were found in a small village in Romania called CosteÅŸti, about 80 km west of the capital Bucharest. These rocks look like blown bubbles and vary in size, some are very large, some are small enough to fit in your hand.
"Trovants from Romania are of very different ages. Trovant do not just emerge from the ground. They are present in sand masses of different geological ages naturally," said Dr Mircea Ticleanu from the Geological Institute of Romania.
"Trovant is a synonym for the German term 'Sandsteinkonkretionen', which means cemented sand. The word 'trovant' is used for the first time in the geological literature from Romania," he continued.
Visitors to the CosteÅŸti site can find a wide variety of spherical and ellipsoidal trovant stones, which grow slowly over time thanks to the presence of rainwater.
They mainly consist of a hard rock core, surrounded by sand which forms a shell. The minerals in the rainwater form a reaction inside that builds up pressure within it, and makes the rock grow and multiply.
Just like the circles on a tree, trovant also shows the layers of the circles when cut. The circle indicates the age or growth period.
Although not alive in the scientific sense, locals and tourists alike describe them as 'living' stones because of the way they have changed over time.
CosteÅŸti is not the only location where trovant stones have been found. A study co-authored by Dr Ticleanu describes them as present throughout the Carpathian region of Romania.
However, the rocks at CosteÅŸti are more famous and are mostly large in diameter. Some trovans in CosteÅŸti are round in shape, while others are oval like eggs. Many of these rocks have intricate twin shapes.
One of the characteristics of CosteÅŸti trovant is the presence of many microtrovant, that is, smaller round tubercles (protrusions) on a large surface.
In addition to the large trovant there are many smaller ones, which are not perfect, but with a pronounced tendency to round in shape.
"All of these trovants were in yellow, fine, medium or coarse sands which also contained fine gravel," the researchers wrote.