Vulcanologists are scientist who study volcanoes. Obsidian, a hard rock from cooled lava, was perfect for arrowheads. Softer soapstone was used for carvings by Inuit artists as well as for cooking pots. Some say rocks are our grandfathers. We hear the story of The Two Sisters, who were turned to rocks at the end of their life journey. An animated story tells the adventures of a volcanic lava rock who finds old friends in a rock collection that includes turquoise for which the Dene have many stories. Archaeologists study human history and Dr. Rudy Reimer from Squamish First Nation describes a rare quartz tool he found in the Heiltsuk Nation territory and show us an adz blade made of nephrite, a very hard, durable rock used for carving wood. Archaeologists excavate through layers of time to find out what people were doing many thousands of years ago. Kai tells us about igneous (volcanic) and metamorphic rocks and shows us how to make a sandstone sedimentary rock. Filmmaker Greg Coyes from the Métis Nation shows the Questers forms of weathering and erosion on the banks of a creek. Rock formations were very important to our ancestors, says Chickasaw Nation astronaut, John Herrington. At the Alibates Flint Quarry in Texas, indigenous people used flint knapping to form arrowheads, knives and axe heads which they traded across the continent. Ochre was mined for thousands of years by Australian aboriginal people to dye paint for rock art and skin clothes. Their mining techniques were very similar to those still used today. In the Pennsylvania area, ancestors dug for oil which they used for fires and as insect repellant. Indigenous technologists were innovative and resourceful.