Tuesday 24 February 2015

PEAR CULTURE

We made our science project on pearl culture and  we completed our project on 22 feb 2015 .We all gathered at Yash Shirole's house at 11:00 am on sunday .In our group there are 9 members  .We made 2 charts .We found information and pictures on goole on wikipedia .We enjoyed a lot creating our project .I thank all my group members for the help an coordination .Our science teacher mrs. Damle ma'am told us about the group project and to create a blog ,this activity was to be individualy done. We enjoyed doing our project so i thank my science teacher for giving us this intresting project.


Here is some of the information about pearls .....




PEARL CULTURE









A curled pearl is a pearl created by a pearl farmer under controlled conditions.


DEVELOPMENT OF A PEARL

A pearl is formed when the mantle tissue is injured by a parasite, an attack of a fish or another event that damages the external fragile rim of the shell of a mollusk shell bivalve or gastropod.In response ,the mantle tissue of the mollusk secretes nacre onto the pearl sac, a cyst that forms during the healing process.Chemically speaking ,this is calcium carbonate and a fiborous protien called conchiolin. As the nacre builds up in layers of minute aragonite tablets ,it fills the growing pearl sac and eventually forms a pearl.




THE PEARL INDUSTRY



The cultured pearls on market today can be divided into 2 categories.
               The first category covers the beaded cultured pearls ,including Akoya south sea and tahiti.These pearls are gonad grown , and usally one pearl is grown at a time .This limits the number of pearls at a harvest period .The pearls are usually harvested after one year for Ayoka ,2 - 4 years for tahitain and south sea and 2-7 years for fresh water .This periculture process was first developed by the british bioligist William Saville-Kent who passed the information along to Tatsuhei Mise and Tokichi Nishiwaka from japan


                The second category includes the non-beaded freshwater cultured pearls ,like the Biwa or chinese pearl.As they grow in the mantle ,where on each wing upto 25 grafes can be implanted ,these pearls are much more frequent and saturate the market completely .An impressive improvement in quality has taken place in the last ten years when the former rice grain shaped pebbles are compared with the near round pearls of today. In the last two years large near perfect rounf bead nucleated pearls up to 15 mm in diameter have been produced with metallic luster.



Some pearl images






END


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pr