Sword-shaped crystals such as these were mined in Ehine, Japan in the late 1800's. Many were smelted to produce antimony, used to harden lead for munitions. The chemical composition of stibnite is Sb2S3.
The black toothpick-shaped stibnite crystals formed first, out of a water solution containing antimony and sulfur. Next, the composition of the solution changed, causing barite crystals to grow on the top, looking like a dusting of snow.