grenaait

grenaait paashaan ka nikat drushya

grainaait (Granite, kanaasham) manibheeya daanedaar shila hai, jiske pramukh avayav sfatik (quartz) aur felspaar (feldspar) hain. yeh aagneya (igneyas) paashaan hai. 'grainaait' shabd ka sarvapratham upayog praacheen itaaliyn sangrahakartaaon ne kiya tha. rom ke shilpkaar fleminiys veka ke ek varnan mein iska pratham sandarbh milta hai.

grainaait pruthvi ke pratyek mein paaya jaata hai. Bhaarat mein bhi yeh prachurata se milta hai. Mysore, uttar aarakat, Madras, rajputana, salem, bundelakhand aur sinhabhoomi mein paryaapt praapt hota hai. himaalaya pradeshon mein bhi grainaait shilaaeain vidyamaan hain. Tamil Nadu ke tanjaavur nagar mein sthit vruhadeshvar mandir vishv ka pehla aisa mandir hai jo grenaait patthar se banaaya gaya hai.

anukram

raasaayanik sanrachana

felspaar saadhaaranat: potaash kism ka orthokles aur maaikroklaain, (Orthoclase and Microline) hoti hai, athva sodiym kism ka plaigiokles (Plagioclase) ailbaait (Albite) ya auligokles (Oligoclase). sfatik saadhaaranataya varnarahit roop mein hi rahata hai, par kabhi-kabhi kuchh neeli aabha rahati hai, jisse grainaait ka rang kuchh neelaapan liye hota hai. ismein abhrak, maskovaait (Muscovite) aur baayotaait (Biotite) bhi alp maatra mein rahate hain. grainaait mein maignitaait (Magnetite), aipaitaait (Apatite), jarakan (Zircon) tatha sfeen (Sphene) bhi bade sookshm manibhon ke roop mein rahate hain. kisi kisi namoone mein haurnableind (Hornblende), gaarnet (Garnet) aur turamali (Tourmaline) bhi paae gaye hain. in khanijon ki upasthiti ke kaaran aise grainaaiton ko kramash: haurnableind grainaait, maskaavaait grainaait aur bayotaait grainaait bhi kehte hain.

grainaait anek rangon ka paaya jaata hai. potaash grainaait gulaabi ya laal rang ka hota hai tath choona grainaait dhoosar ya shvet rang ka. grainaait ka vishisht ghanatv 2.51 se 2.73 tak hota hai.

  • SiO2 — 72.04%
  • Al2O3 — 14.42%
  • K2O — 4.12%
  • Na2O — 3.69%
  • CaO — 1.82%
  • FeO — 1.68%
  • Fe2O3 — 1.22%
  • MgO — 0.71%
  • TiO2 — 0.30%
  • P2O5 — 0.12%
  • MnO — 0.05%

udbhav

grainaait ke udbhav ke sambandh mein vaigyaanik ekamat naheen hain. kuchh vaigyaaniko ka mat hai ki iska udbhav, drav pattharon ya maigma (Magma) ke dheere-dheere thandha hokar thos banane se hua hai. inmein se kuchh iska nirmaan grainaait maigma se aur kuchh baisaalteeya maigma se maanate hain. kuchh vaigyaaniko ka yeh vichaar hai ki poorvasthit shilaaon ke grainaait banaane vaale nirgamon (emanations) ki pravaran (selective) kriya se, athva grainaait banaanevaale abhikrmakaane dvaara, jinko sederahom (Sederholmn) ne aayakari naam diya hai, grainaait bane hain.

Close-up of granite exposed in Chennai, India.

paaya jaata hai

The Stawamus Chief is a granite monolith in British Columbia

bhoo-raasaayanik mool

prayog

puraavastu

Life-size elephant and other creatures carved in granite; Mahabalipuram, India.

aadhunik

Glacier-sliced Half Dome, Yosemite, a classic granite dome and popular rock climb

rock klaainbing

The granite peaks of the Torres del Paine in the Chilean Patagonia

inhein bhi dekhein

sandarbh

baahari kadiyaaain