Hiraikotsu

Hiraikotsu is Sango's gigantic boomerang and her primary weapon. Like the rest of the arms and armor of the people in her village, it was made from parts of vanquished demons. In Hiraikotsu's case, it was made from demon bone. Because of its supernatural material, it's nearly unbreakable and is a very powerful weapon. Hiraikotsu's name can be broken down into three components; Hi meaning 'flying', rai meaning 'come', and kotsu meaning 'bone'. The name itself has been interpreted many different ways, but the one that makes the most sense is 'the bone that flies back'  it was destroyed in chapter 485 but was repaired in chapter 488

Sango uses Hiraikotsu in many different ways. The leather bands at either end allow her to grasp and handle it easily. At six feet in length and what must be fifty pounds or so (Miroku once said Sango must be strong to carry such a heavy weapon everywhere), she handles Hiraikotsu very nimbly. Other than using it as a boomerang, she can swing it and wield it as a melee weapon. In fact she's killed countless demons like that as well as hitting Miroku over the head when he's needed it. Hiraikotsu is also big enough for Sango to use it as a shield when the need arises, and the nature of its material makes it excellent for that purpose.