Shell limestone specific weight: stone density and weight

Shell limestone, or shell stone, is a sedimentary rock, a type of limestone formed from organic remains of marine organisms, mainly shells and their fragments. The main component of shell limestone is calcium carbonate.

The main deposits of shell limestone are located in places of prehistoric seas. When the waters receded over time, the remains of marine creatures that had accumulated on the seabed for millions of years were exposed. Under natural conditions, the skeletons of prehistoric marine creatures were compressed to the hardness of stone.

Characteristics of shell limestone

Shell limestone is a type of limestone consisting mainly of calcium carbonate. Its chemical composition is generally similar across deposits, but actual density, porosity and impurities can differ noticeably.

The popularity of shell limestone as a building material is connected with its natural structure, thermal insulation properties and availability. Depending on porosity, three types of stone are distinguished:

• Grade M15 is a stone of high porosity and, as a result, low strength. Its color is light yellow. Large amounts of sand impurities with high thermal conductivity make the stone “cold”. Blocks of this grade are fragile and light, so they are used for low one-story structures: garages, sheds, bathhouses and fences.

• Grade M25 is a stone of greater strength and lower porosity. It is one of the most common grades in construction practice. The color is light yellow. In strength it is usually comparable with materials used in low-rise construction, but any comparison with brick, aerated concrete or foam concrete depends on the grade and test conditions.

• M35 is the densest shell limestone grade. Low porosity provides higher specific weight and higher strength. The yellow-white color, dense structure and relatively low water absorption allow it to be used for exterior cladding when properly protected from moisture. It is also used in low-rise construction, foundations and cellars where the project allows it.

Extraction and use

Shell limestone is one of the few building materials that nature has given us almost ready for use. Stone extraction consists of cutting geological layers with special machines into blocks of a certain size. The appearance of stone can vary significantly even within one deposit. The stone is easy to saw and process. Depending on further purpose, the surface of the stone may be simply sawn, polished or slightly rough.

Advantages of the material:

• relatively low weight of shell limestone stone,
• low cost,
• unique texture,
• simple processing and installation,
• excellent adhesion due to porous structure,
• low thermal conductivity,
• good sound insulation and frost resistance with proper installation, moisture protection and operation,
• usually compatible with common masonry mortars and finishing materials.

Shell stone is widely used in low-rise construction, interior and exterior finishing. It looks good in landscape projects on household plots: fences, retaining walls, grottoes, fountains and so on. Polished shell limestone tiles impregnated with hydrophobic solutions are used as decorative finishing.