Other stones :
Basalt (B) is a magmatic rock of volcanic depth class. It is a volcanic analogue of gabbro. It consists of basic plagioclase, monoclinic pyroxene and volcanic glass. In minor and accessory quantities may contain olivine, basalt hornblende, magnetite, ilmenite.
The name basalt comes from the Ethiopian “basal” – iron-containing stone. Externally, basalt is a dark micro-granular to aphanite rock
Limestone (V) is a sedimentary rock of carbonate composition that can be of hemogeneous, organogenic and mixed origin. Consists of calcite and / or organic residues of calcite composition. The mineral composition of some limestones in minor and accessory quantities may also include dolomite, clay minerals, quartz, gypsum, pyrite, limonite, carbonaceous matter.
Marble (M) is a metamorphic rock of carbonate composition, which is a product of recrystallization of limestones and dolomites. The main rock-forming minerals of marble are calcite and dolomite. Accordingly, marbles distinguish between calcite and dolomite varieties. In the minor and accessory quantities of marble may include quartz, feldspars, hematite, limonite, pyrite, graphite, organic matter and other impurities, which in different ways affect its quality.
Sandstone (L) is a sedimentary rock of fragile origin. It consists of fragile grains of sandy dimension (sand) and cementitious material. Fragile grains, which make up more than 50% of the total rock volume, are usually the most resistant to physical and chemical weathering by minerals. As a result of mechanical destruction during transfer, they take on a characteristic run-in or semi-roll shape, although they may be acute-angled. Quartz is most common in wreckage, sometimes K-Na feldspar, acidic plagioclase, and light mica.