- Issaquah, Washington (Wikipedia)
Issaquah (/ˈɪsəkwɑː/ ISS-ə-kwah) is a city in King County, Washington, United States. The population was 40,051 at the 2020 census. Located in a valley and bisected by Interstate 90, the city is bordered by the Sammamish Plateau to the north and the “Issaquah Alps” to the south. It is home to the headquarters of the multinational retail company Costco. Issaquah is included in the Seattle metropolitan area.
- Shale (Wikipedia)
Shale is a fine-grained, clastic sedimentary rock formed from mud that is a mix of flakes of clay minerals (hydrous aluminium phyllosilicates, e.g. kaolin, Al2Si2O5(OH)4) and tiny fragments (silt-sized particles) of other minerals, especially quartz and calcite. Shale is characterized by its tendency to split into thin layers (laminae) less than one centimeter in thickness. This property is called fissility. Shale is the most common sedimentary rock.