The Shikon no Tama (四魂の玉; lit. Jewel of Four Souls) or "Shikon jewel", is a magical jewel in the anime Inuyasha that was created by the battle of the great miko (priestess) Midoriko and powerful youkai (demons.) The balance of energies created a jewel in which they are always battling with neither winning over the other and which has great powers that can be used for good or for evil.
Physically, it is a sphere that appears to be made of some sort of crystalline material prior to the accident that shattered it. When purified, the jewel is a soft pink color, however the more tainted the soul and wishes of the person holding it, the more the color turns to a lurid black-violet. It is somewhere between a marble and a ping-pong ball in size when complete, but the shards of the Shikon-no-Tama are irregular in size and shape.
Before the series begins, Kikyo was entrusted with its guardianship, but it leads to her untimely demise and Inuyasha (who loved her) being sealed to a tree for 50 years, both because of Naraku's deception. The jewel was burned with Kikyo and only returned through a reincarnation of Kikyo, Kagome coming back from the future because of the Jewel's power. Kagome eventually unsealed Inuyasha, however the jewel was lost to a demon-crow. In attempting to retrieve it by shooting the crow with an arrow, Kagome accidentally shatters the jewel, which is now in thousands of shards (Shikon no Kakera). Inuyasha-tachi (Inuyasha, Miroku, Kagome, Shippo and Sango) are attempting to collect the shards and stop Naraku.
