For anyone who has performed the Umrah or Hajj pilgrimages, they will have probably noticed the coolness under foot when they stepped onto the marble floors of the mataf within the Grand Mosque. Many have debated the reason behind the cold feeling, despite the intense heat that may reach 50 degrees Celsius in the summer. Some may think that there are air conditioners under the floor, and this information is incorrect.

The General Presidency for the Affairs of the Two Holy Mosques says that the main reason was the type of Thassos marble used at mataf, which may be the largest surficial marble application in the world.

During the reign of King Khalid, he ordered the expansion of mataf in the year 1398 AH, and its floor was furnished with Thassos marble for the first time. This marble reflects the sun’s rays, and in turn, the heat too during the daytime.

According to the presidency, the characteristics of the coolness of the floors have attributed to the quality of the marble used in the Grand Mosque. It is noteworthy that Saudi Arabia has been importing, for decades, the famous Greek Thassos marble because it reflects light and heat, which no other type of granite and marble does.

Thassos marble is the most white and rare marble in the world and its grain is of small size. It receives its name from the Greek Island Thassos located in the Aegen Sea, from where it has been extracted since ancient times. The Greeks were among the first peoples to discover marble and to develop its uses throughout the ages.

This marble is distinguished from others by its crystal white color, and it is one of the purest and most solid natural stones. The thickness of the marble used at the Grand Mosque reaches five centimeters. It is also distinguished by the fact that it absorbs moisture through minute pores during the night, and during the day it excretes what it absorbed at night, which makes it always cool even in high temperatures.

This material has been described as the heat-dissipating smart marble where its high whiteness purity was attributed to the stone’s dolomite-rich crystal formation. This mineral’s 2 mm crystal sheet configuration was then linked with two important factors, including that of minimal porosity and an increased thermal conductivity which would both help to maintain its cooler temperature.

Saudi Arabia imports this marble in the form of huge rock pieces, and they are processed in private Saudi factories and under the supervision of qualified technical cadres to cut these pieces into tiles of certain sizes and with special standards.