On Earth, there are thousands of varieties of stones. And without a doubt, these are the most common formations on the planet, because the Earth itself is a stone covered with a thin layer of soil. Rocks, as we also call them, are completely diverse in their characteristics, composition, value, but above all in density. This is simply an indispensable material used in all kinds of construction when choosing the right stone. Density in this case becomes a fundamental criterion.
Birth of stone
Everyone understands that solid rocks did not appear from the air in an instant. For their formation, as well as for the origin of all life on the planet, it took millions of years of evolution and special conditions created by nature itself.
Any stone is a hardened magma of prehistoric volcanoes that erupted everywhere on the planet billions of years ago, when it was still young and looked more like the surface of modern Venus. And the process itself, and the conditions, and the influence of many external factors and constantly changing climatic conditions - all this directly influenced not only the birth of the stone, but also the formation of its varieties, completely unlike each other.
Therefore, the specialist will determine the density of the stone without any devices, knowing only its variety.
The main types of stone
There are only two main types of natural stone - light and heavy, differing primarily in structure, texture and susceptibility to weathering.
Porous sedimentary formations, such as sandstone, limestone, dolomite, rubble, and others that do not have frost resistance, have a high degree of moisture absorption, and are highly susceptible to weathering belong to the lungs.
These are types of stone whose density is extremely low. They are distinguished by friability, instability and inability to withstand high loads. These species belong to cheap and rather unreliable building materials.
A heavy stone has a corresponding density; it belongs to groups of igneous and (less commonly) metamorphic rocks. These include: marble, granite, syenite, diorite, porphyry, basalt and many others, the hallmark of which is frost resistance.
Properties of natural stone
It is resistance to low temperatures that determines the main property and quality of the stone. Such rocks are automatically ranked as having a low degree of water absorption, therefore, they are resistant to weathering.
Frost resistance (freezing cycles) has 9 grades: F10, F15, F25, F35, F50, F100, F150, F200, F300 - it is quite obvious that this is an indicator of degrees below zero Fahrenheit. F10-F50 - a low indicator inherent in a light stone, its water resistance (softening coefficient) ranges from 0.9 to 1. Starting with the F100 brand, a heavy stone with a high density is determined, it has a water resistance of 0.5-0.75 - these are indicators characteristic of granite and diorite.
But it should also be noted that every stone has foreign impurities, and in many respects their density depends on it, because other inclusions make it porous and subject to weathering. This is determined by the Mohs scale of hardness and depends on what compressive load the stone can withstand.
What is the density of stone
The density of the stone is determined on a scale of 1 to 20, and it is expressed by the ratio of the mass of the rock with a similar mass of water of the same volume. Light rocks matter from 1 to 2, the average density of the stone in this case varies from 2 to 4. All rocks with a value above 4 are heavy, respectively, have a high density. Gemstones such as sapphires, rubies, emeralds and especially diamonds are the most durable and heavy in this regard, their indicator is from 10 to 20.
A similar determination of the density of the stone is expressed in the mechanical effect on it - during compression, shock loading and abrasion test. There is another way to determine a stone for density - by immersing it in heavy liquids. Both methods have nothing in common, so it is worth considering them separately.
Immersion of stone in heavy liquids
By immersing a stone in “heavy water”, its density is determined quite accurately and within just a few minutes.
Despite the fact that this method gives an absolute result and takes very little time, it is used infrequently because of its high cost. The costs of this should be financially justified, therefore, the method is used mainly to determine the density of precious stones, in particular to identify fakes.
Everything is simple here: the density of “heavy water” and diamond, for example, is the same, and if a synthetic fake is dipped into it, it will immediately float to the surface like a cork. And if the density of a stone of natural origin is equal to the density of a liquid, it will not float and will not sink, but will remain in a soaring state.
Mechanical inspection method
By checking the stone mechanically, its density is also determined quite accurately, only in this case samples of rocks that are not related to precious stones are tested for strength.
This method is quite simple, does not require special expenses, but it also takes a lot of time. For this, a hydraulic press is used, creating a load to determine the hardness of the stone. If the rock is not sufficiently resistant to a certain pressure force or has a porous structure, it will begin to crack and crumble, if it has the necessary hardness and viscosity, it will remain unharmed.
The mechanical methods of impact also include impact loading and checking the strength on a cast iron circle by the friction method. So to determine the strength of any rock or mineral is very simple, but what density of stone is necessary for a certain type of work is a topic for a completely different article.