رخام

(تم التحويل من الرخام)
الرخام

الرخام هو صخر كلسي متحول، يتكون من الكالسيت النقي جداً (شكل بلوري لكربونات الكالسيوم CaCO3). يستعمل في النحت، وكذلك يستعمل كمادة بنائية، وأيضاً في العديد من الأغراض الأخرى. وقد تكون تحت ظروف نادرة من الضغط والحرارة الهائلتين في جوف الأرض .

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

أصول الرخام

أنواع الرخام

Natural patterns on the polished surface of "landscape marble" can resemble a city skyline or even trees (see photo).
Blocks of cut marble at the historic mill in Marble, Colorado
Black Dębnik marble portal (17th century) of St. Wojciech's Church in Kraków
رخام من إيطاليا

بعض أنواع الرخام المهمة تاريخياً, سميت على اسم مواقع محاجرها, مثل

الرخام اللون الموقع الدولة/المنطقة
أبيض بكين أبيض الصين
رخام أسود Dębnik پولندا
رخام أسود Kilkenny أيرلندا
Boticena and Onyx(Green) باكستان
Brač جزيرة براتش كرواتيا
رخام بني Chęciny پولندا
رخام كرارا أبيض أو أزرق-رمادي كرارا إيطاليا
Connemara marble أخضر Connemara أيرلندا
Danby marble Danby ڤرمونت
Durango Marble Coyote Quarry المكسيك
Fauske النرويج
Llano Pink Central Texas
Luni marble Luni إيطاليا
Macael اسبانيا
مكرانة أبيض رمادي الهند
Nabresina Trieste إيطاليا
Parian marble Fine-grained semitranslucent pure-white جزيرة پاروس اليونان
Penteli Marble أبيض خالي من العيوب مع مسحة صفراء باهتة منتظمة Penteli اليونان
Proconnesus Marble جزيرة مرمرة تركيا
رخام أحمر Ruşchiţa رومانيا
Rouge de Rance أحمر Rance بلجيكا
أبيض ملكي أبيض الصين
ثاسوس Snow white, White, Grayish white, White with pink veining جزيرة ثاسوس اليونان
أبيض ڤيتنام أبيض رمادي ڤيتنام
Yule Uniform pure white ماربل، كولورادو كولورادو


أنواع الرخام البيضاء, مثل كرارا من إيطاليا والأبيض الملكي وأبيض بكين من الصين, have been prized for sculpture since classical times. This preference has to do with the softness and relative isotropy and homogeneity, and a relative resistance to shattering. Also, the low index of refraction of calcite allows light to penetrate several millimeters into the stone before being scattered out, resulting in the characteristic "waxy" look which gives "life" to marble sculptures of the human body.

الانتاج

According to the United States Geological Survey, U.S. domestic marble production in 2006 was 46,400 tons valued at about $18.1 million, compared to 72,300 tons valued at $18.9 million in 2005. Crushed marble production (for aggregate and industrial uses) in 2006 was 11.8 million tons valued at $116 million, of which 6.5 million tons was finely ground calcium carbonate and the rest was construction aggregate. For comparison, 2005 crushed marble production was 7.76 million tons valued at $58.7 million, of which 4.8 million tons was finely ground calcium carbonate and the rest was construction aggregate. U.S. dimension marble demand is about 1.3 million tons. The DSAN World Demand for (finished) Marble Index has shown a growth of 12% annually for the 2000–2006 period, compared to 10.5% annually for the 2000–2005 period. The largest dimension marble application is tile.

In 1998, marble production was dominated by 4 countries that accounted for almost half of world production of marble and decorative stone. Italy and China were the world leaders, each representing 16% of world production, while Spain and India produced 9% and 8%, respectively.[1]

In 2018 Turkey was the world leader in marble export, with 42% share in global marble trade, followed by Italy with 18% and Greece with 10%. The largest importer of marble in 2018 was China with a 64% market share, followed by India with 11% and Italy with 5%.[2]


. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

السلامة المهنية

Dust produced by cutting marble could cause lung disease but more research needs to be carried out on whether dust filters and other safety products reduce this risk.[3]

In the United States, the Occupational Safety and Health Administration (OSHA) has set the legal limit (permissible exposure limit) for marble exposure in the workplace as 15 mg/m3 total exposure and 5 mg/m3 respiratory exposure over an 8-hour workday. The National Institute for Occupational Safety and Health (NIOSH) has set a recommended exposure limit (REL) of 10 mg/m3 total exposure and 5 mg/m3 respiratory exposure over an 8-hour workday.[4]

التحلل بالأحماض

Acids damage marble, because the calcium carbonate in marble reacts with them, releasing carbon dioxide (technically speaking, carbonic acid, but that disintegrates quickly to CO2 and H2O) :

CaCO3(s) + 2H+(aq) → Ca2+(aq) + CO2(g) + H2O (l)

Thus, vinegar or other acidic solutions should never be used on marble. Likewise, outdoor marble statues, gravestones, or other marble structures are damaged by المطر الحمضي.

التحلل الجرثومي

The haloalkaliphilic methylotrophic bacterium Methylophaga murata was isolated from deteriorating marble in the Kremlin.[5] Bacterial and fungal degradation was detected in four samples of marble from Milan cathedral; black Cladosporium attacked dried acrylic resin[6] using melanin.[7]

الاقترانات الثقافية

Jadwiga of Poland's sarcophagus by Antoni Madeyski, كاتدرائية ڤاڤل، كراكوڤ
Relief on the Marble Door of the Hagia Sophia in Istanbul

As the favorite medium for Greek and Roman sculptors and architects (see classical sculpture), marble has become a cultural symbol of tradition and refined taste. Its extremely varied and colorful patterns make it a favorite decorative material, and it is often imitated in background patterns for computer displays, etc.

Places named after the stone include Marblehead, Massachusetts; Marblehead, Ohio; Marble Arch, London; the Sea of Marmara; India's Marble Rocks; and the towns of Marble, Minnesota; Marble, Colorado; Marble Falls, Texas, and Marble Hill, Manhattan, New York. The Elgin Marbles are marble sculptures from the Parthenon in Athens that are on display in the British Museum. They were brought to Britain by the Earl of Elgin.


. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

الرخام الاصطناعي

Marble dust is combined with cement or synthetic resins to make reconstituted or cultured marble. The appearance of marble can be simulated with faux marbling, a painting technique that imitates the stone's color patterns.

معرض صور

انظر أيضاً

الهامش

  1. ^ Strategic positioning study of the marble branch. CEPI Brief N° 6. tunisianindustry.nat.tn
  2. ^ Comtrade. "Comtrade Explorer - Snapshot HS 2515 (Marble, travertine, ecaussine and other stone)". United Nations Commodity Trade Statistics Database. Retrieved 31 January 2020.
  3. ^ Foja, A.F. (1993) Marble industry: its socioeconomic, environmental and health effects among marble worker/producer households in Romblon. Philippines University Thesis. fao.org
  4. ^ "CDC – NIOSH Pocket Guide to Chemical Hazards – Marble". www.cdc.gov. Retrieved 2015-11-27.
  5. ^ Doronina NV; Li TsD; Ivanova EG; Trotsenko IuA. (2005). "Methylophaga murata sp. nov.: a haloalkaliphilic aerobic methylotroph from deteriorating marble". Mikrobiologiia. 74 (4): 511–9. PMID 16211855.
  6. ^ Cappitelli F; Principi P; Pedrazzani R; Toniolo L; Sorlini C (2007). "Bacterial and fungal deterioration of the Milan Cathedral marble treated with protective synthetic resins". Science of the Total Environment. 385 (1–3): 172–81. Bibcode:2007ScTEn.385..172C. doi:10.1016/j.scitotenv.2007.06.022. PMID 17658586.
  7. ^ Cappitelli F; Nosanchuk JD; Casadevall A; Toniolo L; Brusetti L; Florio S; Principi P; Borin S; Sorlini C (Jan 2007). "Synthetic consolidants attacked by melanin-producing fungi: case study of the biodeterioration of Milan (Italy) cathedral marble treated with acrylics". Applied and Environmental Microbiology. 73 (1): 271–7. doi:10.1128/AEM.02220-06. PMC 1797126. PMID 17071788.

وصلات خارجية