Tuesday, November 29, 2011

Spectacular Sapphires

  Did you know that Sri
Lanka is one of the biggest exporters of sapphires in the world? At one point we were even called ‘Ratna Dweepa’ or Gem Island because of the sheer abundance of precious stones. The town of Ratnapura of Gem Town has always been known as the centre of the Sri Lankan Gem industry. The famous Portuguese traveler Vasco da Gama id known to have said “Ceylan has the all the fine cinnamon of the Indies and the best Sapphires “.

Historically, our island was known for its strong elephants, beautiful pearls and the bluest of the blue sapphires. Three of the best known (and two of the largest ) sapphires in existence come from Sri Lanka-The Logan Sapphires, the Star of Bombay and the Star of India. Two of them are currently in the United States after their owners bequeathed them to the
 
Smithsonian and the National Museum of Natural History.
  There are many people who claim that Sri Lankan sapphires are far superior to sapphires from any other country. Sapphires are type of rare gemstone found in places such as Australia, Madagascar, Burma, Sri Lanka and Thailand. It is a variety of a mineral called Corundum which is a type of Aluminum Oxide. It is the same variety of mineral as the Ruby, and all other colors of this mineral apart from the red and orange are called Sapphires. The orange variety of Corundum is called Padparadscha, and is found Sri Lanka and is highly prized and valued. 
   Gems are traditionally mined and this is often referred to as gemming in Sri Lanka. Usually pits are dug close to rivers where secondary alluvial (sedimentary) deposits are usually found; gems such as sapphires and even rubies are fond in such environments. To gain access to this sort of gem baring gravel, miners dig pits that are often between 5 and 50 feet deep, by hand, in order to always be aware of the nature of the sediments of the they are removing from the pits. Once it is the correct depth, the pits are then dug out horizontally in several directions to maximize mining area and to minimize surface damage, allowing farm land and paddy fields to be in existence on the surface. The water that gathers is constantly pumped out, and the remaining muddy sediments are swirled around
 in cone shaped baskets until heavier stones called jathi settle at the bottom of the basket.
    Sri Lanka is particularly well known for the brilliant blue of its stones. Unlike the stones from Australia, which have a darker and denser colour, jewelers around the world look at Sri Lankan sapphires as a source of brilliance that hasn’t been seen since the Kashmiri mines stopped producing sapphires.
  The colour of sapphires tends to change depending on other elements such as iron and titanium inside the sapphire. Therefore sapphires can range from regular colours such as blue and purple to pink and yellow. In Sri
Lanka, 
traditionally miners and gem cutters have been heating precious stone to improve their colour, and sapphires are treated the same way. A certain type of sapphire called the Geuda sapphire which is often a milky and cloudy blue is heat treated in order to get the brilliant ‘Ceylon blue’ that jewelers have come to expect from Sri Lankan stones.
  Although Ratnapura was traditionally known as the centre of the gem industry in the country, there are several other mines that are several other mines that are significant gem producers around the country. Bibile Sapphire mines (Ceylon blue and yellow pushparaga sapphire ), 
Elehara Gem Fields, Pelmadulla sapphire mines ( where Ceylon blue and Padparadscha sapphires are mined ) and the Nuwara Eliya mines are some of the better known mines.



















Sunday, November 27, 2011

Endemic Birds of Sri Lanka

Layard’s Parakeet

    Scientific Name –Psittacula 
calthropae Common Name –Alu Girawa. The name of this endemic breeder commemorates the British naturalist Edgar Leopold Layard. It is also referred to as the Sri Lanka Emerald Collared Parakeet. Its color is mainly green and it measures up to at least 29cm long including a tail of up to 13cm. The adult has a bluish-grey head and back,separated by a green collar. There is broad black chin stripe and the tail is blue tipped yellow. The female is similar, but has all black break and less green on the face than the male. Immature birds are mainly green, with an orange bill.
    Layard’s Parakeet is bird of forests, particularly at the edges and in cleanings, and also gardens. It is locally common and undergoes local movements, driven mainly by the availability of the fruit, seeds, buds and blossoms that make up its diet. It less gregarious than some of its relatives, and usually in small groups outside the breeding seasons, when if often feeds with Brahminy Starlings. Its flight is swift and direct, and the call is distinctive as it’s raucous chattering. It nests in holes in large trees, laying 3-4 white eggs. It appears on the 50 cents postal stamp and the new 500 rupee note. 






Sri Lankan Hanging Parrot


  Scientific Name- Ioriculus berylinus Common Name – Gira Maliththa or Pol Girawa. This is a small parrot which is a resident endemic breeder in Sri Lanka. It is the size of a House Sparrow measuring only 13cm long with a short tail. The adult is mainly green with a red crown and rump. The nape and black have an Orange tint. The chin and throat are pale blue. The beak is red and the irises are white. Immature birds lack the orange hue to the back, have a duller rump, and have only a hint of orange on the crown. They have a faint blue throat, orange beaks and brown irises. It is less gregarious than some of its relatives, and is usually alone or in small groups outside the breeding season. Its flight is swift and direct, and the is a sharp whistled twiwittwit….twitwitwit. Its move meant are driven mainly by the availability of the fruit, seeds, buds and blossoms that make up its diet. 

It is a bird of open forest and lives on trees, never descending to the ground. Its breeding habits are highly remarkable. It nests in hole in trees, laying 2-3 white eggs. It breeds in the first half of the year, and sometimes again in July-September. This brilliantly colored little parrot is found everywhere in the his up to 4,000 feet, and in the north-east monsoon it ascends a thousand feet higher; it also inhabit the low-country wet zone and parts of the dry zone to the south of the Northern Province. The Sri Lanka Hanging Parrot is featured in the 15 cents postal stamp and the new 1,000 rupee note.