Stone Stories 2

Now that we're familiar with the classes of stones, let's delve even further!

Properties of stones:

Stones	Classification	Suitability
Granite	Igneous	Most suitable for engineering works such as bridge abutments, piers, sea walls, dams
Serpentine	Igneous	Ornamental works and quality building works
Sandstone	Sedimentary	For pavements, roof tiles, ornamental works and heavy engineering works
Limestone	Sedimentary	For pavements, roofing and in the manufacture of cement.
Laterite	Metamorphic	For rough stone masonry work and stone pitching
Marble	Metamorphic	Flooring and decorative ornamental works

Other general purposes of stones as building materials are:

• Foundations and Walls

          - sawn stones for substructure
          - limestones and sandstones for walls, piers and abutments

                         

          

• Facing and Architectural Items

         - Granites and sandstones are sawn from slabs or split from semi-finished product blocks to make
           facing slabs and stones, stairs and landings, parapets, etc.

        

• Road Construction

- curb stones that separate roadways from sidewalks

         

 - paving blocks for pavements

- cobblestones as reinforcement for slopes of earthworks and banks of water   basins

• Underground Structures and Bridges

Formwork to make slabs

Stone finishes

          - Granite and limestone in slab and stone forms are used for these; in other words, igneous and

            sedimentary rocks.

          - Tunnels and above-water elements of bridges are built of granite, diorite, gabbro and basalt. 

          - Face stones and facing slabs for tunnels and bridges are given rock face, grooved or fluted finishes.

• Heat- and Chemically-Resistant Items

          These are manufactured from non-weathered rocks, which are rocks that have not been exposed to

          the elements that cause wear, such as frost and chemicals.Most of them are made from chromite, 

          basalt, andesite and tuffs for high temperature working conditions.

Now that you know, you need not stay stoned when it comes to stones! (Yes, the pun is intended.)

Stone Stories

(Hate walls of text? Then here's a way to cheat: watch these videos to get the gist of our topic today!)

Igneous rock:

Sedimentary rock, and how it evolves into metamorphic rock: 

The origin of this geological matter seems as though it is more of a contradiction rather than a fact of life.  People have long believed that stones - or rather rocks - are created from scratch but in actual geological context, the rock formation process is actually a cycle whereby the rocks are created, eroded and reformed once again.  The oldest rock was formed approximately 4.6 billion years ago.  Thus, one can only imagine how that rock was formed.

The diagram below shows the formation process of stones/rocks:

Different types of rocks reside in different strata, as illustrated below:

Volcanic activity plays a vital role in the formation of rocks.  As magma cools in the magma chambers, intrusive igneous rocks and minerals such as granite are formed.  Once the volcano erupts, the lava drools down causing it to eventually cool down.  This will create - or rather, form - extrusive igneous rocks.  In the long run, these rocks will be eroded by wind and rain. The eroded materials then find its way into the ground and waterways.  What next?  The sedimentary materials that rest at the bottom of oceans, lakes and rivers will accumulate.  Over a long period, the new layers will cover and compress the older layers. The older layers will become harder due to extreme pressure and in turn form sedimentary rocks.

Natural stone has been used in most constructional applications namely, green design. Energy price has increased and the need for energy conservation when heating or cooling buildings have recently brought it to the fore. Dimension rock is an example of a sustainable natural rock which is created by the separation of natural bedrock underlying all land on every continent.

Rock formation actually involves the formation of igneous rocks, sedimentary rocks and metamorphosis rocks.  Once the sedimentary rocks are formed, it metamorphoses into metamorphic rocks.  This depends on the temperature and pressure exerted on the layers of rock. These rocks actually undergo a process of stretching and compression.

The demand for beautifully cut, perfectly formed rocks and stones has birthed an industry for artificial stones, which are synthetically manufactured stones. These stones are gaining footage and popularity for the level of control afforded by synthetic production.  Artificial stones are made from crushed natural stones bonded together using Portland cement with a minimum water/cement ratio. Not all artificial stones become part of a structure; sometimes they can stand solo as a decorative piece in a home. Luxury home are particularly partial to these decorative stones. In short, artificial stones are manufactured for the ease of meeting the increasingly stringent demands of clients.