Volcanic Glass Eyeglass / Sunglass Necklace. Made with Snowflake Obsidian, which is formed when felsic lava from a volcano cools quickly and is volcanic glass that forms as igneous rock...got that? This very natural and neutral colored glasses necklace has round faceted Snowflake beads, dark cubed and square shaped fire polished crystals, and gold tone spacers. Measuring 27.5 inches long with adjustable stretch ends to fit most frames, this necklace was only too hot to handle long, long ago.