noun Descargar 🔗Compartir Pechstein A natural glass, rich in microscopic crystallites, formed by the rapid cooling of lava or magma Examples : "The sharp edges of the pitchstone found near the volcano were used by early humans to make tools. " Los bordes afilados del pechstein encontrado cerca del volcán fueron utilizados por los primeros humanos para fabricar herramientas. geology material Chat con IAJuego de vocabularioPracticar lectura