Vintage Gemstone Bolo Tie - Western Cowboy Necktie with Unique Style and Timeless Elegance According to the Rock Identifier App the stone is Obsidian. Which is a naturally occurring volcanic glass formed when lava extruded from a volcano cools rapidly with minimal crystal growth. It is an igneous rock. Obsidian is produced from felsic lava, rich in the lighter elements such as silicon, oxygen, aluminium, sodium, and potassium. It is commonly found within the margins of rhyolitic lava flows known as obsidian flows. These flows have a high content of silica, giving them a high viscosity. The high viscosity inhibits diffusion of atoms through the lava, which inhibits the first step (nucleation) in the formation of mineral crystals. Together with rapid cooling, this results in a natural glass forming from the lava. SHOP with CONFIDENCE ✅ Fair Pricing, Lower than Others on Poshmark ✅ Smoke Free & Pet Friendly Environment ✅ Poshmark Ambassador II & Mentor ✅ On Platform since 2016 ✅ Shipping Within 24 Hours ✅ Top 5 🌟 Seller/Ratings ✅ Check My LOVE ♥️ NOTES ✅ I Sell to Buy On Poshmark ✅ Reasonable Offers Welcome ✅ I Counter Unreasonable Offers ✅ I BLOCK Offensive Offers I Re-List Often, If Interested Please Get It Before It Disappears! Thank you for visiting my closet. 🙏🏻 🇺🇸 NOTE: I do my best to accurately show the colors of items, but I am not a professional nor do I have lighting or equipment. Colors my appear different based on lighting /devices / monitors.