In this review, the major types of natural glasses are presented to a ceramic science and engineering audience with acknowledgement to the specialized vocabulary and scientific issues in geology and earth sciences, and some major research focuses for the technical glass community are highlighted.  In the first section, terminology and compositions are summarized.  Among the types of natural glasses briefly summarized are volcanic and plutonic glasses (including those broadly termed basalt, obsidian, and volcanic ash), impact glasses (including tektites and Libyan Desert glass), and miscellaneous natural glasses (combustion, friction, and high energy glasses including pseduotachylites, fulgurites, and glasses resulting from dike intrusion and similar geologic events).  Next the incidental anthropogenic glasses resembling some of these natural glasses are summarized, including trinitite and nuclear blast glasses, archaeological vitrified hillforts, bulk vitrified contaminated soils, and metallurgical slags.  In the second section, some longstanding research areas connecting natural and technical glasses are reviewed.  Structure and composition similarities and differences are discussed, including considerations of glassy versus crystalline fraction, redox state, and water content.  Next, alteration of natural and related anthropogenic glasses is considered, highlighting relevance to archaeological dating, nuclear waste management, and the interaction with biologically accelerated alteration.  Considerations for extraterrestrial occurrence of glass is then summarized, focusing on lunar and Martian geological evidence.   Finally, new or renewed interest in collaboration between technical glass and natural glass communities is suggested in the areas of pressure effects on glass structure, relaxation of glass over time, and use of waste rock as raw material for new glass-based products.