## 5 Material Uses
### Basalt  
Basalt is generally a black to gray-colored volcanic rock, and is usually fine-grained due to the fast cooling of lava on the Earth's surface. It may be porphyritic, and contain large crystals in a fine matrix, vesicular, or frothy scoria. Unweathered basalt is black to gray in color. Basalt has a firm chemical definition. It is described as a total alkali silica (TAS) diagram. Basalt is an igneous rock that contains SiO\({}_{2}\) in the range of 45-52% and less than 5% of the total alkalis (K\({}_{2}\)O + Na\({}_{2}\)O)\({}^{3}\). Neighboring rock types, such as basaltic andesite, basanite, picrite (picrobazalt), and trachybasalt, including more distant types such as phonotephrine or andesite, can appear similar and can be easily mistaken for basalt in many cases [29]. The mineralogy of basalt is characterized by the presence of calcite plagioclase feldspar and pyroxene. Olivine is a significant constituent. Additional mineralspresent in relatively minor amounts include iron oxides, such as magnetite and ilmenite; iron-titanium oxides, such as titanium-augite and sphene; and spinel.  
The fundamental quality characteristics of basalt, such as compressive strength, high abrasion resistance, and chemical resistance, make it useful in industrial applications. Basalt can be converted into fine, superfine, and ultrafine fibers. Compared to other types of fibers, basalt fibers are deemed superior in terms of thermal stability, heat and sound insulation properties, vibration resistance, and durability. Basalt has replaced asbestos in almost all its applications and is three times more effective in isolating heat than reinforced plastic (1 kg of basalt provides equivalent reinforcement of 9 kg of steel). Typical basalt applications include crushed stone, concrete aggregates, railroad ballast, production of high-quality textile fiber and floor tiles, acid-resistant equipment for heavy industrial use, rock wool, basalt plastic pipes, basalt plastic reinforcement bars, basalt fibers, roofing felt, heat-insulating basalt fiber materials, and glass wool.  
Crushed basalt ranging from 25 to 45 mm can be employed in the rock wool industry, and 30% of the product that is smaller than 25 mm is used as aggregates. The application of basalt as an aggregate is not preferred due to the availability of cheap alternative materials such as limestone, despite the fact that the physical engineering qualities of basalt are superior to those of limestone. Thus, basalt is considered a good option for durability. Moreover, basalt can be used as a dimensional stone for buildings.  
Boulder lining materials were added as stones in the mortar mixture. Technical operations are required to exploit basalt stone and prepare for other operational requirements. When the lining is covered with stones, the surface imposes considerable resistance to flow; thus, the surface is sufficiently rendered, and the coefficient of rugosity is increased. Thus, stone linings are appropriate in situations where the loss of head is not an important factor and where stones are available at an affordable cost.  
More extensive use of newly available nondestructive methods for testing the quality of completed work can provide independent backup for routine inspections during construction and can help minimize the number of inspections. A suitable rock type can be selected by applying the TOPSIS criteria. However, another issue involves the manner in which the methodology should be used to achieve high accuracy and easy application.