Among the rocks used to produce heat-insulating and acoustic building materials, volcanic water-containing glassy rocks are increasingly being used. A feature of volcanic water-containing glasses is their ability to expand during heat treatment. Besides perlite, other volcanic glasses known by various names also have this special feature: obsidian, pitchstone, vitrophire, and others. The common property of all these rocks, which determines their expanding power, is the content of water in them, being in various forms of linkage. The main role in the process of their pore formation during bloating belongs to water and various gases located in closed pores. Obsidian is expanded at temperatures of 1050...11500C. The lowest average density of 200 ... 350 kg/m3 (in a piece) is obtained by heat treatment of obsidian for 3 ... 10 minutes (depending on the size of the sample).

According to the modern terminology, the term «perlite» means natural glassy mountainous rock that has the expansion feature when heated causing high porous pumice-like material. Scientifically, in the first place, perlite (containing different quantities of water) itself that is hydrated volcanic glass, in the second place, pechstein that is even and fairly strong hydrated glass, in the third place, obsidian that is glass containing little water, in the fourth place, the so-called porous perlite that is scientifically regarded as little porous pumice, can be pertained to technical perlite. Thus, in Armenia according to technical significance «perlite», glassy mountainous rock, divided into perlite and obsidian. The igneous rock consists of volcanic glass the water content of which does not exceed 1%. In Armenia, in ancient times obsidian was expanded and used in the upper layers of the dome of the three-floored temple Zvartnotc. Expanded obsidian can be used as artificial porous aggregate for lightweight concrete of different designation. Obsidian is expanded at temperature of 1050-1150°C. The lowest average density of 200-350 kg/m3 (in a piece) is obtained at thermal processing of obsidian with the coarseness from 5 to 20mm and the duration of 3-10 minutes. On the basis of expanded obsidian heat-insulating and acoustic materials can be developed: lightweight and cell concrete and plastering with cement and gypsum.

Since the Covid-19 eruption in 2020 designers from all over the world started to concentrate their efforts to increase the awareness of the population through visual methods and prevent the spread of the disease. As the germ itself is invisible to the naked eye, graphic designers created an iconic visual identity 3D image of a particle, which became the widespread inspiration for future propaganda and informational posters. Furthermore, the visualization of the virus particle was not enough to influence the wide scope of people; thus, the new problem for designers became to make such posters that could reveal virus vs human “relations”, taking into account gender characteristics as well. The article consists of analytical research on gender-based graphic design’s role in the prevention of viruses throughout history. The main problem is how graphic design projects influence the decrease of the virus spread and how gender equality-cantered design contributes to it. First time in the article are presented the basic principles of poster design considered for all genders to present the serious message of the urgent prevention of the virus. In the article, the works of designers are analysed and reviewed as well. The significance of the article is emphasizing the importance of gender equality in design visualization to increase the influence of them on people’s behaviour.

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