What is Asphalt?

The word Asphalt originally derived from latinization of the Greek work Asphaltos and based on late latin words asphalton or asphaltum. In ancient civilizations asphalt is used for pasting cement joints and in the Middle East it was vastly used for road paving and waterproofing which are current major applications of asphalt.

Basically asphalt is combined set of aggregates from crushed rock, sand, gravel, slags or bitumen. Nowadays, use of by-products and wastes are also common – such as sludge or construction wastes – resulting in higher sustainability of asphalt. The result of this mixture is a black, sticky and high viscosity blend in solid or semi-liquid form which is relatively homogenous and suitable to expand over flat layers.


How is asphalt produced?

Asphalt is produced through mixing and blending several aggregates at an asphalt plant in high temperatures usually from 150-180 degrees Celsius. Asphalt plans could by mobile as well in order to produce the asphalt blend on site.

Producing Asphalt at different temperatures

In order to achieve different specifications for different applications, the asphalt can be made in different conditions which most effective one is the temperature. Below is a general categorization of asphalt making:

Asphalt Production Method

Temperature of the Blend (°Celsius)

Suitable Bitumen Used for the Blend

Hot Mix Asphalt 120-190 Penetration Bitumen
Warm Mix Asphalt 100-140 Soft Penetration Bitumen
Half Warm Asphalt 70-100 Soft Penetration Bitumen
Cold Asphalt Without Heating Emulsion or Foamed Bitumen


Asphalt Applications

While major application for asphalt is road paving, considering the variety of specifications, it can be used in several sectors including the below:

  • Transportation (roads, railway beds or airport runways…)
  • Building construction (floorings, roofing…)
  • Industrial (ports, landfill caps …)
  • Recreation (playgrounds, running tracks, tennis courts…)
  • Agriculture (greenhouse floors, barn floors…)

Layers of Asphalt Paving

Asphalt Paving consists of several layers, from ground to top consequently as below:

  • Sub-Base and Sub-Grade: Preparation of the foundation with suitable clay or sand base aggregates
  • Base Course: Most important layer to distribute the force traffic through the pavement layers
  • Binder Course: Binder courses are implemented to stand the shear forces below the asphalt surface and reduce rutting sufficient stone-on-stone contact and stiff and modified binders such as Gilsonite.
  • Surface Course: Surface course is the top layer of the pavement and stands high traffic and environmental stresses while providing an even profile for the user and enough texture to ensure minimum and safe skid and rutting resistance.

Asphalt Binder

Asphalt Binder is a bituminous layer that can be added either to the Surface layer or as an extra layer called binder course below the surface to make a stronger bind with the base course.

Surface Asphalt Binder is an asphalt emulsion designed for tack coat for patching, paving, and coating. Asphalt Binder increases adhesion of bituminous concrete and coatings.

Asphalt binder as binder course is an intermediate course between the base course and the surfacing material consisting of medium-sized aggregates bonded together by bituminous material such as Molten Gilsonite.

gilsonite in paint

Gilsonite in Paints and Stains industry

Generally using Bituminous paints is a known and common procedure for certain painting which requires weather or corrosion resistance and it is a very economical approach in many industries such as foundry to use bituminous paint.


Considering the low quality of bituminous paint, in certain applications there is a requirement of using a BITUMINOUS PRODUCT but with superior quality which results in applying Gilsonite in Paint as an additive, since Gilsonite preserves the Bituminous properties while having proper physical characteristics to be controlled and spread (or sprayed) properly on any surface, unlike any other bituminous paint.

Gilsonite in Paint

gilsonite in paint industry

Considering its unique properties – caused by millions of years of natural occurrences underground – applying Gilsonite in Paint results in excellent bonding with almost any material to create a protective coating paint. using of gilsonite in paint is one the most important of gilsonite applications. Gilsonite in paint industry is used as an additive with relatively lower costs compering to additives with similar performance which has caused its high usage in pipe coatings, anticorrosive paints and underbody paints in several industries including vehicle industry and pipe manufacturing.

Gilsonite in Wood Stains

When applying Gilsonite in Wood Stains, the actively bituminous content of the Gilsonite acts as a binder with the wood surface making a strong finish that is less likely to fade. At the same time, the coloring effects of Gilsonite provides a higher resolution colors to the pigment.

Advantage of using Gilsonite in Paint

The advantages of using Gilsonite in Paint are numerous; still the below can summarize most of the Gilsonite Advantages in Paint and Stains:

  • Superior bonding characteristics
  • Highest resistant to pigment fading comparing to other paint additives
  • Possibility to make transparent pigments while preserving quality aspects
  • Stable against UV lighting
  • Providing a deep and rich coloring to wood stains

The proper grades of Gilsonite in Paint are Gilsonite Selects 325 and Gilsonite Selects 347 which is supplied by Zista Gilsonite from special mines in Iran along with a proper and high tech processing of the material in our China facility.



Utah Gilsonite Mine

History of Gilsonite in Utah

Gilsonite was firstly known by Native Americans in the Utah area which then were offered to White-Men as coal for blacksmithing. Since using Gilsonite instead of coal is hazardous, the material soon became famous and several people including Samuel Gilson started working on development of material for different industries.


Eventually by obtaining most of the resources ownership in Utah Gilsonite mines, Samuel Gilson was able to make the first Gilsonite company in 1903 called the Gilson Asphaltum which later on was purchased by Chevron and partners and the name changed to American Gilsonite company in 1948 which owned all large veins of Utah Gilsonite mines along with most of smaller veins of Gilsonite in the Utah area and the situation has continued during the years.


Geologic Setting

Utah Gilsonite Mine veins which are somewhere around 50 million years old, are located in Tertiaryaged in the Uinta Basin. The explored formations of vein are found in Duchesne River, the Wasatch, Uinta and Green River. In the Wasatch Formation Gilsonite can be exploited from eastern edge which has escaped the Oil shale above.


Utah Gilsonite Mines are founded in long, vertical, northwest-trending veins in a 60-mile by 30-mile block. The veins’ width can vary with an average of 1-2 meters. The veins of Utah Gilsonite mines are interestingly continuous and long. The vertical veins are mostly located in the Green River oil shale, so they are more vertically extensive to the northwest where they are not as deeply eroded.

utah location


The primary reserve estimation of Utah Gilsonite mines was 45,000,000 tons which after years of exploitation with an average of 20-60,000 tons (with a spike of 470,000 tons in 1907 to feed the Gilsonite gasoline refinery), it had come down to 5,000,000 tons in 1980; estimated by American Gilsonite company. Therefore, already most of that ore from Utah Gilsonite mine has been extracted.

However, three factors could increase the total reserve of Gilsonite:

  1. Possibility of discovering new veins in Utah Gilsonite Mines in addition to increased reserve estimations of smaller veins which are already discovered in Utah area.
  2. Emerging new resources of Gilsonite outside Utah Gilsonite mines, including Iran Gilsonite veins estimated to be over 30,000,000 tons and only 2,000,000 tons have been exploited already. Another emerging resource – which is currently supplying to American Gilsonite Company to help economics of production and covers for lack of Utah Gilsonite mine reserves – is Colombian asphaltite with similar characteristics to Gilsonite and large reserves found in Magdalena Basin in Colombia estimated to have around 20,000,000 tons of untouched reserve; causing USA oil companies and American Gilsonite Company to divert investments and purchasing power to these resources.
  3. Scattered around the world, there are also different reserves of Natural Bitumen similar to Utah Gilsonite mine which could cause large scale discoveries any time in the future. (Gilsonite Global Reserves)