How to identify a genuine Rudraksha seed.

Nowadays, rudraksha seem to come in all shapes and sizes, and available at every little shop that sells alternative medicines, including a host of online stores. But make sure you get the real one. Imitations look real but don't work! Here's how to identify a genuine Rudraksha seed.
Artificial Rudraksha is often made from the wild berry seeds or nuts. But these berries cannot be made as real as the ones that are in the genuine ones and therefore easily be detected by an experienced eye. Here the facet (Mukhi) means the deep lining running through the diameter of a Rudraksha bead. Looking at these deep linings-facets one can recognize real Rudraksha. ‪There are a number of methods for identification of fake Rudraksha like:
Water Test ~ Sometimes rare Rudraksha beads like GauriShankar Rudraksha or a Trijuti are made by artificially joining two or three Rudraksha with the help of glue etc. In case of doubt, such Rudraksha bead should be placed in boiling water for 20-30 minutes. A sharp discolouration will take place at the joint in case of artificial Rudraksha.
There is another water test that is conducted as well. The bead is placed in a glass of water. If it floats it is rejected. However, this test is not very reliable because ; An unripe but genuine Rudraksha will also float in water. Fake Rudraksha bead made of wood and impregnated with lead will also sink in water. Rare Rudraksha beads like One Mukhi are sometimes made by tampering with higher Mukhi beads. This Rudraksha will also sink.
Copper Coin Test ~ It is a general belief that a Rudraksha bead when placed between two copper coins will rotate slightly either towards the right or the left. This happens due to the physical and magnetic properties of the Rudraksha beads. This test requires a high level of expertise and the buyer generally buys the bead that rotates towards right.
Eye Test ~ The Mukhis of a natural Rudraksha look like closed lips with deep natural partitions. Sometimes Rudraksha are faked by sticking thorny parts of one Rudraksh onto another one. This difference could be caught by a 10x lens. However, none of these tests are full proof. The best way to buy an expensive rudraksha is by taking an Xray or by CT scan of that rudraksha gives 100% accurate results but it is much expensive. But it is suggested that buy Rudraksha from a trusted authorized supplier.
Rudraksha are available from 2 Mukhi till 29 Mukhis. The five faced Rudraksha are found easily and abundantly. One faced Rudraksha round variety has never been found till date and is thus a myth. A variety of Rudraksha called 1 mukhi half moon is thus sold in its place which is genuine and belongs to a family tree of Rudraksha. This bead is found easily and price is also not high. However there are suppliers who sell this half moon variety also at exorbitant prices taking advantage of the rarity of round 1 Mukhi Rudraksha. Round 1 Mukhi Rudraksha however is the most highly sold bead and is faked in many forms by unscrupulous suppliers. Many of these beads are made from berries and betel nuts and Areca nuts. Some have a stem implanted in them artificially to give a real look. Also some suppliers sell fake 1 Mukhis which have Serpent, Trishul, Lingam etc carved on them. A real Rudraksha does not have these markings. Rudraksha having 2,3,4,6 and 7 faces are found abundantly and hence their prices are not high. Fake Rudraksha are made by carving extra lines in these lower Mukhi beads to obtain the rare and higher priced higher Mukhi beads.
Also some scrupulous people fake Gauri Shankar Rudraksha by gluing together two Rudraksha beads. But these can be again detected by little experience and awareness. It is not very difficult to recognise a real Rudraksha. On account of its increasing importance and price, it is made artificially. the Nepal suppliers of today are making these by carving out extra lines in a lower Mukhi bead to get a higher Mukhi bead, or hiding extra lines to obtain a rare lower Mukhi bead and even by gluing together parts of Rudraksha beads to obtain another Rudraksha. Thus these fake Rudraksha look externally like real Rudraksha and thus have to be examined more carefully. 
Fake beads can also be made from wood, cork, gum or from a type of clay. As well as from the inner wood of the plant species Aquillaria agallocha and from the wood of Chestnut (Akrod) plant. The Rudraksha should be brought from a genuine supplier who is accountable to the people. 
Authentic Rudraksha will both float and sink depending on how much moisture is trapped in the Bead so there can be no valid test for Authenticity based on sinking or floating. If the authentic Bead is a couple of years old and really dry from being in a collection box it will float because it is totally dry. But still it is an authentic Bead. Another thing to be noted is that Rudraksha being a natural product, it is available in many qualities from low, medium, high to collector. A buyer should avoid low quality beads which are light weight, have broken surfaces and are unshapely and have extremely dry surface. These beads rarely provide any effect. One should go for Rudraksha which are heavy, bright, lustrous, shapely and emit a positive vibration.!
Om Namah Shivaya!!