Khiinii miru are unetched, spherical black and white banded agates. This type of stone is commonly known as "Sulemani agate", or "Solomon agate", named after King Solomon and originally supposed to be from his legendary mines. They appear to be part of a long established production whose historical center was Western Asia and may date back as far as 2500 BC. Of course, many beads found today on traditional necklaces are not anyway near that old. The pair displayed on the above picture is set up at the bottom of a santer tasan, and contrasts with the overall blue hue of the necklace. From a strictly commercial point of view, these are too worn and damaged to have any value. But their social, cultural and aesthetic value is, of course, a different matter.
In the course of history round banded agates seem to have found their way to the Himalayan cultures, especially the Tibetan one where there have become known as Bhaisajyaguru, "the Medicine Buddha" (Sman-bla in Tibetan) beads. Many of them are probably just a few hundred years old. Both Suleimani and Bhaisajyaguru refer to the same kind of stone, basically black agate with lighter banding. The cult of Bhaisajyaguru being very popular in Tibet (as well as in Mongolia, Tibet, Korea and even Japan), it is likely that the stone was attributed some talismanic or medicinal properties by the popular religion, as for Dzi-beads (see previous post).