People have often found unusual stones on the ground, from which a rather pungent smell emanated. Those who touched these stones often felt worse, after a while the skin became covered with ulcers. If the stone was struck with something, it suddenly became hot or exploded. So it was with the Ertomsky stone, found in the summer of 1976 on an islet of the Vashka River ten kilometers from the village of Ertoma in the Udora region of the Komi ASSR. The stone attracted the attention of fishermen with its bright white color with a metallic shade. When one of them hit him with a stick, the stone caught fire. At first, at the break, it became dazzling white - it glowed strongly, but then it darkened. A sharp specific smell emanated from the stone, barely perceptible crackling rustles were heard. When a file was lightly passed over it, the stone sparkled, and when trying to saw it, it caught fire again,flaring up with a fairly strong flame.
The study of Ertomsky and other similar stones led the researchers to the idea that these are "tricks" of the so-called black lightning, that is, ball lightning, but which has not yet heated up, "has not matured", therefore it persists in the environment for a long time.
Black lightning has significant energy, contains inorganic and organic substances, metals and other elements that can enter into chemical reactions. That is why, when it comes into contact with a tree, black lightning charcoals or ignites it. Sometimes the substance of black lightning remains on objects and they can ignite. During dry periods, black lightning can cause wildfires. When exposed to soils, sintering, melting, glass-like formations appear.
In addition, the substance of black lightning has the ability to penetrate into the soil or mineral and concentrate there, forming the so-called clathrate compounds - that is, cemented soil particles. In this case, unusual shine and even its own glow in the daytime, shine around such a mineral are possible. Its other properties are strange odors, crackling, warming up, mechanical ignition, fire and even explosion. In humans, this stone can damage mucous membranes or eyes.
People’s ignorance about black lightning, psychological unpreparedness to meet them sometimes lead to dangerous consequences. There was a case when a climber stepped on a stone containing the substance of black lightning, received severe burns and died two weeks later.
However, if we talk about the Ertomsky stone, then over time its properties changed. In some cases, the stone even had a healing effect on the skin. Judging by the isotopic ratios, the substance of the stone is of purely terrestrial origin, although in a number of countries such stones are often called stellar, solar or lunar.
From the book: "SECRETS OF THE TWENTY CENTURY" I. I. Mosin