jyotish men ratnon ki vishesh mahima hai. maharshiyon ne in ratnon ke un gunon ko pahchana jinse ye grahon se niklne vali rashmiyon ko avshoshit kar lete hain aur inhen dharan karne vale par kisi grah vishesh ke parne vale dushprabhavon men kami ati hai aur achche prabhavon men vriddhi hoti hai. lekin alg-alag grahon ke lie alg-alag ratn hote hain aur har ratn apne se sanbaddh grah ki rashmiyon ko hi ekatra karta hai, anya kisi grah ki rashmiyon ko nahin.
yadi do ratn dekhne men ek jaise bhi hon jaise pukhraj evan sunhla ya nilam evan nili ya manikya evan garnet to bhi jyotish ke anusar in donon ki karya kshamata men bahut antar hota hai. atah kisi ratn ko hath men lene se pahle sarvapratham prashn uthta hai ki yah kaun sa ratn hai. dekhne men bahut kuch ek jaise do ratnon ke mulyon men atyadhik antar ho sakta hai jaise ki 5-6 kairet ke ek hire ka mulya das se bis lakh rupye tak ho sakta hai jabki kritrim hire ka keval das se bis rupye aur yadi donon ko mila diya jae to shayad dekhne men kritrim hira hi jyada sundar dikhai dega.
atah yah param avashyak hai ki ratn ki pahchan sahi se ho aur aj ke yug men jabki mashinikaran ka prachalan hai evan mashinon dvara bhi prakritik ratn jaise hi ratnon ka nirman sanbhav hai. aise men prakritik aur kritrim ratnon men antar karna evan ratnon aur uparatnon men antar kar pana atyadhik kathin ho gaya hai. keval dekhakar yah bata pana atyant kathin hai ki diya hua patthar ratn hai, uparatn hai ya kritrim ratn hai. prayogshala men anekanek vidhiyan hoti hain jinse ham ratnon ki pahchan kar sakte hain. ratn ke mukhyatah nimn gunon ko prayogshala men parikshan kiya jata hai.
apekshik ghanatva (density)
har ratn ka apna ghanatva hota hai. ise mapne ke lie ya to alag alag apekshik ghanatva ke dravyon men ratnon ko dalakar yah jancha jata hai ki unka ghanatva kisse kam hai aur kisse jyada. iske atirikt ghanatva haidrostaitik bailens upakaran dvara bhi ghanatva ka map nikala jata hai.
apavartanank (refractive index)
har ratn ka apna apavartanank hota hai jiske dvara uski pahchan ki ja sakti hai. kuch ratnon ka dohra apavartanank (double ri) hota hai. rifraiktomitar dvara yah apavartanank asani se mapa ja sakta hai aur is prakar se manikya, jiska apavartanank 1.761 aur 1.770 hai, ko garnet se alag kiya ja sakta hai jiska ki ghanatva to manikya jitna hi hai lekin apavartanank usse kahin adhik 1.775 aur 1.790 ke madhya keval ek hai.
dhruvan (polarisation)
kuch ratn dohra apavartan (double refraction)darshate hain aur unmen bhi kuch ratn ek akshiya (uniaxial)evan kuch dvi akshiya (biaxial) hote hain. polairiskop ke madhya men ratn ko rakh diya jata hai aur donon or polraijing filtars tirchi avastha (cross position) men laga die jate hain. is sthiti men prakash ek or se dusri or nahin pahunch pata hai. lekin ratn rakh dene par vishesh konon par prakash dikhne lagta hai jisse ki ratn men dhruvan ki pahchan ki jati hai.
maikroskop men ratn ko dekhna:
ratn prakriti men anek varshon men ban pate hain. jin dravyon evan gaison dvara ye bante hain ve iske andar samahit ho alag se dikhai dete hanai. ye antahsth dravya v gais (inclusions) ratn ki pahchan karne men atyant sahayak hote hain. inke adhar par yah batana bhi sanbhav hota hai ki ye kis sthan se prapt kie gae hain. kritrim ratnon ke dravya v gais prakritik dravyon v gaison se kafi bhinn hote hain kyonki kritrim vidhi men kristalikaran (crystalisation) bahut tivra gati se kiya jata hai.
kathorta </h2
moh skel men kathorta 1 se lekar 10 tak darshai jati hai. iske antargat 10 prakar ke khanij padarth lie jate hain jinki kathorta 1 se lekar 10 tak hoti hai:
1. tailk 3. kailsait 5. epetait 7. kvatrj 9. korandam 2. jipsam 4. florait 6. aerthoklej 8. topaj 10. hira
adhik kathorta vala khanij kam kathorta vale khanij par kharonch dalne men saksham hota hai. kaun si kathorta vale khanij ki kalam ratn par kharonch dalne men saksham hai is adhar par uski kathorta ki pahchan ki jati hai.
pratidipti (fluorescence)
kuch ratn parabaingni prakash men pratidipan (fluorescence) darshate hain. is vidhi ke antargat ratn kisi bhi tarang (wavelength) vali rashmiyon ko avshoshit kar usse adhik tarang vali rashmiyon ko utsarjit (emit) karta hai jisse ki uska rang badla hua najar ata hai. pratidipt (fluorescent) manikya ko jo ki garnet se bhi is vidhi se alag kiya ja sakta hai.
spektroskop dvara parikshana
yah ek bahut hi achchi vidhi hai ratnon ko pahchanne ki. ismen ratn ke dvara jo rashmi avshoshit ki ja rahi hai evan jo sanpreshit, uska ek varnakram (spectrum) dekhakar do ratnon men antar kar sakte hain. chitra men rubi aur garnet ka varnakram dikhaya gaya hai jiske dvara donon men antar karna bahut hi asan hai.
uparyukt sabhi vidhiyan prayog men kuch kathin hain. aj ke is kanpyutar yug men ratn ki pahchan ke lie vishesh ilektraenik upakaran bhi upalabdh hain jinke dvara ratn ko keval sparsh karakar pahchana ja sakta hai ki vah kis shreni ka hai. ye upakaran ratn ki tap chalkta evan paravartakata par adharit hote hain. in upkrnon se bahut hi suvidhapurvak kuch sekand men hi ratn ko uparatn ya kritrim ratn se alag kiya ja sakta hai.