Orange, Yellow, Brownish Stains and Alteration on White Marble at El Montazah in Alexandria, Egypt

ABSTRACT

Brightly colored stains on the white marble at the Tea pavilion and marble statues in Renaissance style trigger a scientific investigation to determine their origin. Staining and alteration of white marble in El Montazah site have been studied by using different microscopic techniques, polarizing microscope (PLM), reflected light microscope, light microscope and scanning electron microscope (SEM). Moreover, several samples have been examined by X-ray powder diffraction, Energy Dispersive X-ray analyses (EDX), FTIR spectroscopy and biological analysis.

The results indicated that different factors contribute to form stains on white marble. In the Tea pavilion at El Montazah site, staining can essentially be attributed to the alteration of pyrite. Microbial deterioration, black stains and the reactions between the organic matters with the alkali solutions have a dominant influence in the discoloration and staining of marble statues at El Montazah site. Also, FTIR in the brownish areas from the marble statues confirmed the presence of Paraloid B-72. Probably a part of marble staining was caused by the alteration of Paraloid B-72, which was used in the past to consolidate or as an adhesive to preserve the marble.

KEYWORDS:

• brownish stains
• deterioration
• discoloration
• El Montazah
• staining

Disclosure statement

No potential conflict of interest was reported by the author.