The unit of weight of Panna Stone is Carat. In metric scale this is equal to 200mg. Whenever one talks of Rate of Panna stone it is given in CARAT. Generally Panna Stone is available from Rs.450 per Carat to Rs.41000 per Carat.
But lower varieties of Panna Stone can be found at Rs.200 per carat.
The price of Panna Stone, like any other gemstone depends on its colour and clarity. More eye pleasing a Gemstone with shining water inside more price will it command.
To be sure of originality always buy Govt. Lab Certified Gemstones.