Pietra Gray Marble (Armani Gray Marble)

But one of the salient features of this stone is the presence of fractures that are usually filled with white materials such as calcite or secondary quartz. These veins have given unbeatable beauty to the marble. Pietra Gray Marble (Armani Gray Marble) is quarried in iran and is called lashotor domesticly.

Background Colors of Pietra Gray Marble(Armani Gray Marble)

Based on its theme color and veins, pietra gray marble has been sorted in two colors of black and gray with beautiful white streakes throughout its surface. Moreover, pietra gray stone is available in two forms of limited-vein and spider-vein patterns. Pietra gray with the black theme has been sorted to polished and matt surface. Nevertheless, pietragray marble with the gray background is more in demand thesedays.

Marble Mines of  Pietra Gray Marble(Armani Gray Marble)

Marble stones are mostly consist of calcium carbonate, so they have been applied as decorative and construction materials for many years due to their strenghth and beauty. Recently marbles are extracted from either open cast or underground quarries. Extraction methods and the block sizes vary based on the quarry. Each extracted block comprises 6 paralell sides whose dimensions are as follow:

• Length : 2.2 To 3 Metres
• Width: 1.2 To 1.5 Metres
• Height: 0.9 To 1.2 Metres

1) Pietra Gray Marble (Armani Gray Marble)Mines

The main mines of pietra gray marble are located in the south of isfahan province. Although pietra gray is originated in iran, it has been produced in other countries such as china , turkey,and italy as well. Pietra gray mines have the extraction capacity of about 3000 tonage blocks monthly and reserves of about 360,0000 tones of blocks annually.

1-1) Classification of Pietra Gray Marble Blocks

Based on some quality parameters, obtained blocks can be classified as below:

• Cracks
• Amount of veins: the lower number of streaks results in higher quality.
• Tonage
• Block size
• Cleanliness: marble blocks with no stains are considered as clean ones.

*these critera determine the price of the marble as well.

Types of Pietra Gray Marble(Armani Gray Marble)  Processing

pietra gray marble is processed variously and it is available in both forms of tiles and slabs in the stone markets. In the process of production and processing of this building stone, epoxy is used to fill the surface pores of the stone. In tile method processing, colorless mastic or the same color as the background is used to fill the very fine surface veins of the stone. The indirect uv method directs the special resin into the veins of the stone and stabilizes it. This action causes a good processing in polishing of the stone.

Different types of processing of this stone include:

• Polished pietra gray: the bright surface of pietra gray marble increases the price of it and the appretiation of the purchasers. By polishing the stone the brightness of the marble is enhanced. Therefore, it leaves a smooth and glossy surface. Polishing time varies between 45 – 60 minutes depending on the dimensions of the block.
• Honed pietra gray: in this type of processing silicon carbide or diamond particles are applied on the surface of the marble to remove cutting marks and unevenness of the marble surface. The result will be a matt and shine free surface.
• Leathered pietra gray: all types of stones can be leathered. Similar to honed pietra gray , in leathering process the leathered finish will be of a matt and shine free surface. In this processing the weak parts of the marble are broken off and an uneven surface is created.
• Bushhammered pietra gray: the bushe hammered marble has a rustic look and reduces the sliperriness of the stone surface and makes it perfect for outdoors. Formerly stones were hammered manually but nowadays modern machines are applied for hammering the stones.
• Tumbled pietra gray : this processing creates an antique look of the stone. For this aim a chemical or mechanical method is used.
• Cut broken pietra gray (manually or machine-processed): the stone is processed in a non-abrassive manner then it is cut by an ax manually or by machine. Due to its strength, pietra gray has been cut broken to increase its friction as a result its slipperiness decreases. So it is applicable to outdoor spaces.
• Windshield and guillotine pietra gray

Dimentions

Pietra gray marble tiles are available in standard dimensions of 40 lengths 60*60. Super sorts of pietra gray slabs can be produced in the following dimensions:

• 220 * 150
• 300* 195

Moreover, it can be cut to customized sizes based on the customers’ demands.

Industrial processing hubs

the main industrial hubs are located in isfahan province , in mahmood abad industrial estate, doolatabad and rezvan shahr districts. Moreover, there is another industrial hub in tehran province which is known as shams abad industrial estate which is considered as one the most important industrial processing hubs in iran.

Tiles and slabs packings for export

1) Using pallets: two types of pallets are available for loading: doored and doorless pallets.
Tiles are put together vertically in terms of width across the pallet and the pallets are tightened by robust belts.

• Pros: reasonable prices,more loading capability in comparison to trestle and pallets with doors, convenient for carrying to different floors of buildings.
• Cons: it is prone to damages during evacuation and loading if it is not done with due care, the likelihood of being chipped in case of inaccuracy.

2) Using wooden crates: it is similar to the pallet floor with the difference in the handles at the two sides of the pallets that are connected to eachother by bolts. On the other hand, plastic tools are used for tiles corners and some styrofoams are applied to the bottom of the crates to prevent chipping of the tiles.

• Pros: more economic in comparison to wooden pallets, also convenient for carrying lengthy stones.
• Cons: inappropriate for carrying in long distances (exporting), likelihood of being chipped in case of insufficient accuracy.

3) Using metal pallets: it is similar to wooden pallets and is made of steel profile.

• Pros: more robust and tolerant to stone weight comparing to wooden crates.
• Cones: more expensive than using wooden crates.

4) Transporting without packing : in this method of transporting and moving the stone, which is done only to transport the stone in tile and longitudinal dimensions, the stones are placed separately in the truck.

• Pros: no payment by the buyer when loading.
• Cons: possibility of cracking and breaking of the stone while transporting the stone.

Applications Of Pietra Gray Marble (Armani Gray Marble)

Different kinds of pietra gray processing have different applications. For instance , polished and honed pietra gray are applied in flooring , interior walls and steps of the buildings. Architects use leather bushhammered, and tumbled pietra gray marble as yard paving and decorative elements in façade of the buildings. Cubic pietra gray marble are applied as sidewalks paving. Constructors usually use windshield and guillotine pietra gray as decorative stones in building exterior design.

Polished pietra gray is not normally used in building façades since it loses color under the sunlight.

Pietra Gray Marble Target Markets

Due to its cost-efficient price and luxury, pietra gray marble is exported to whole world.it is so popular in international stone market but some of the main importers of pietra gray blocks are china, oman ,saudi arabia, , uae, italy and turkey.

Chemical And Physical Analysis Of Pietra Gray Marble Stone (Armani Gray Marble)

Complementary Stones for Using with Pietra Gray in Constructions’ Design

Pietra gray is a natural stone with a dark background, so designers normally match it with stones of light themes in interior design of buildings. For instance pietra gray can be applied with crystal stones having light background to make the envirnomet look lighter and more spacious.

Similar Stones to Pietra Gray Marble

due to its high quality and elegance, the price of pietra gray marble is higher than similar marbles to this stone. Maku black and najafabad marbles are much the same as pietra gray but with a more affordable price.

Types of Pietragray Extraction from Mine To its Cutting Types in the Factories

At first, pietragray blocks are extracted from the mine by using wire cutting machines then it is crushed by wedge and fars method to divide them into smaller pieces. Afterward, the blocks are cut to size by wire cutting machine and loaded by trucks to be transported to processing factories.

In the processing plants different methods are applied to cut the blocks in forms of slabs and tiles. Basically, stones with more regular geometric shape and larger dimensions like a rectangular cube are turned into slabs with a saw machine in cutting factories. Those in smaller sizes or without good geometric shapes are tiled with a peg machine. However, pietra gray cutting method is different from other natural stones’ cutting, due to its texture. Unlike the other stones, it is usually cut from one direction.