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).

In the production of crushed stone, lithoidal pumice and perlite sand, it is advisable to separate and segregate the obsidian. Wherein, the separated obsidian is converted into production waste. By the expansion of obsidian it is possible to obtain an ultralight large grain porous material and thereby solve environmental issues - to dispose of waste products. The expansion of volcanic glass (obsidian) occurs due to gases, primary (magmatic) and secondary (hydraulic) water, which is located in the pores. During the expansion, under heat treatment, the gases expand about 4 ... 5 times in the pores, which contributes the expansion. Expanded obsidian can be used as a filler for lightweight concrete. Obsidian is expanded at temperatures of 1050-115°C. The lowest average density of 200 - 350 kg / m3 (in a piece) is obtained by heat treatment of obsidian with a particle size of 5 to 20 mm for a duration of 3-10 minutes. Depending on the requirements for lightweight aggregates, by adjusting the firing temperature and duration, it is possible to obtain expanded obsidian with the necessary physical and mechanical properties. It is revealed that more durable concretes are obtained with cement consumption of 350 ... 380 kg. Depending on the average density of lightweight concrete 400 .. 1350 kg/m3, the compressive strength is 0.2 ... 16,9 MPa. Light monolithic products with improved characteristics of heat resistance and thermistance, having an average density of 180-200 kg/m3, compressive strength of 1.2–1.5 MPa, frost resistance of 25 cycles, after which the strength changes to 1.0–1.3 MPa, heat resistance to 800–850°C, and thermistance to 600–650°C. By the thermal conductivity coefficient determination it was possible to reveal that in the temperature range of 20-60°C, the thermal conductivity coefficient changes by 0.002 W/mK, i.e. from 0.044 to 0.046 w/mK. Thus, the obtained monolithic blocks can be very successfully used as heat-insulating materials, which will retain their properties throughout the operation of the facilities. The requirements for mechanical strength and decorative properties for sound-absorbing materials compared to thermal insulating materials are higher, since they are used for internal linings. Thus, the obtained monolithic blocks can be very successfully used as heat-insulating materials, which will retain their properties throughout the operation of the facilities.

In modern conditions, one of the ways allowing the construction company to be competitive in the market is the use of modern high – quality and, at the same time, cheaper building materials. Many technogenic formations, in particular solid waste are valuable technological raw materials and can be involved in technological redistribution in order to obtain composite building materials. In the production of crushed stone, sands from lithoid pumice and perlite, it is advisable to produce separation and separate obsidian. In this case, the separated obsidian turns into production waste. The expantion of obsidian will allow to obtain a large porous ultralight material and thereby solve environmental issues – recycle production waste. On the base of expanded obsidian, it is possible to obtain new types of effective composite thermal insulation and acoustic materials (cellular concretes and acoustic plasters), which have high performance properties and expand the range of effective building composite materials.

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Today, the decline in soil fertility progress, therefore, special attention paid to the search for new, including non-traditional sources of raw materials that allow cultivating agricultural crops. It is propose to use expanded obsidian as a soil aerator. Obsidian is a volcanic rock, consisting of volcanic glass in which water content does not exceed 1%. A characteristic feature of this stone is the ability to expand under heat treatment. The expansion of obsidian is possible to implement at temperatures of 1050… 1150 °C. It has been shown that due to obsidian expansion it is possible to obtain a light porous filler with an average density of 200… 350 kg/m3, where the heat treatment of 5… 10 mm grains should be performed under temperatures from 1050 to 1150°C, during 3…5 minutes. The mechanical strength of the expanded obsidian is due to the thickness of the internal partitions of the pores and depends on the total porosity. Increased porosity decreases the strength of the expanded obsidian grains as the internal partitions of the pores become thinner. Relatively high mechanical strength develop grains with less porosity, ie lower coefficient of expansion. At the same time, the nature of the external surface of the grain has a significant influence on the mechanical strength. The melted surface,under other equal conditions provides mechanical strength increase of the expanded obsidian.