Things to Consider While Buy Natural Stones – Shopping Guide

“Oh my! I am completely confused looking aisle upon aisle of natural stone stock/inventory you have shown me.”

These are common expressions when a buyer visits first time at the premises of World of Stones USA. Not here, everywhere it happens when a buyer looks at ranks demonstrating a variety of stones even after touching many of those. It is true that the catalog mostly contains brand names of stones, which usually differ from one brand to another.

Thereby, our natural stone consultants got inspired to write a stone shopping guide as a reader-friendly post accessible on the web for all. The content of the natural stone buyer guide is as follows.

• Stone Types
• Applications
• Properties of Natural Stones
• How to Test Properties
• Natural Stone Textures
• Natural Stone Maintenance
• Natural Stone Costing

Introduction to Natural Stone Types Based On Their Origin

If you are tech-savvy and use Google-like search engine to know about the origin of natural rocks, which we are quarrying and obtaining dimension stones for construction and other purposes, you may have come across three major geological terminologies: 

1. Igneous rocks: It comes from molten volcanic stuff like magma.
2. Sedimentary rocks: It forms when eroded fragments of other rocks is settled and compressed in the crust of the earth.
3. Metamorphic rocks: It forms when igneous and sedimentary rocks are transformed due to pressure and heat.

However, in the construction industry  people are accustomed to only two segments of rocks:

1. Siliceous rocks: Which contains Silica or sand as the major element. Quartzite, Granites, Slate, and Sandstone are ideal examples of it.
2. Calcareous rocks: Which contains Calcium as the major element. Marble, Limestone & travertine  are following in this category.

In industry, natural stones are used in different forms , such as:

Whole Stones

Cubes

Cubes used as stacked stones as structural elements. Today, it is used in hardscapes only.

Slabs

Slabs used on floors and walls in moderate thickness in interior & exterior applications.

Veneer

Stone veneers  are thin slices sticking on the wall surfaces, be it exterior or interior.

Crushed Stones: 

• Gravel
• Pebble
• Cobble
• Boulder

Defining Areas/Spaces for Natural Stone Applications

With the basic introduction, I hope now it is time to learn which stone type are the choices for different areas like interior, exterior, and landscape or hardscape. The major categories are:

If you are interested in details, we have prepared an Infographics  to take a birds-eye view.

The Most Common Types of Natural Stones Used In the Industry:

The biggest trouble in the natural stone industry is colloquial naming. The majority of stones are known by their local names instead of their generic types. For instance, Bluestone  and Flagstone are not generic or technical names but used based on some of their properties like colors and shapes.

Thereby, I have presented a short & sweet list of the most common and generic types of natural stones  used in the present day in the US and elsewhere.

Siliceous Types of Natural Stones

Quartzite Natural Stone

Quartzite is a metamorphic type of rock. It has high silica content – nearly 90% of the total mass.

The Best Application Areas:

Interior Spaces

Kitchen countertops, cabinet-tops, tabletops, floors, and other heavily used surfaces including floors and stairs.

Exterior Spaces

Façade, porch, and patio paving. Pool decks, paths, walkways, and driveways.

Granite Natural Stone

Granite is a mostly igneous-origin type of rock, but in many instances, it is found as sedimentation-origin. It has high availability around the planet.

The Best Application Areas:

The same as Quartzite.

Sandstone Natural Stone

Sandstone is a sedimentary type of rock. It contains sand particles. It is available across the globe and many sea floors.

The Best Application Areas:

The same as Granite. It is highly used as the structural elements and architectural elements in the interior as well as exterior places.

Slate Natural Stone

Slate is a metamorphic type of rock. It contains volcanic ash and clay particles.

The Best Application Areas:

Due to fissility, it has limited applications but is considered as the best material for roof tiles. Exterior applications are many. It is the best choice as a paving material.

Learn About the Different Properties of Natural Stones & How to Test It with Simple and Handy Tools

If you want your natural stone material for a long service lifespan within the surrounding environment contexts, durability is the term used for it. According to common sense, stones in the construction industry have the following kinds of possible threats.

Impacts: 

• Hit by other strong objects,whether by accident or intentionally.
• Structural load, be it dead or live traffic.
• Earthquake, a storm like natural disasters.

Climate:

Heat, cold, wind, humidity, rain, frost/thaw cycle, and Sunrays 

Chemicals:

Water, oil, acid rain, spills, corrosion, sewage, pH fluctuations, and carbonation.

The results  of these threats are:

• Splitting
• Crumbling
• Cracking

Metrics of Durability:

The American Society for Testing and Materials has defined the following metrics to measure durability factor in for the construction material, including natural stones. However, it is pure scientific terms, and you might get puzzled by it, so I have tried to simplify it the most possible ways.

• Absorption and specific gravity
• Modulus of rupture
• Compressive strength
• Flexural strength
• Abrasion resistance

How to Measure Durability?

Applied geologists take help of testing laboratory to measure the durability factors of natural stones by taking various approaches, including:

• Accelerated Laboratory Durability Tests : freeze-thaw cycling, wetting–drying, and salt crystallization resistance.
• Environment Tests : complex environmental testing in test cabinets.
• Exposure  site testing.

Unfortunately, an ordinary client cannot afford to pass through such testing and mostly rely on the results hanging on the walls of the office of stone supplier or distributor. Now, I am going to give you some practical and handy tools and methods to measure various parameters of durability factors in the natural stone industry.