2.2.1.30 GeometryCollection
The GeometryCollection type represents a Geometry that is defined as the union of a set of Geometry instances. GeometryCollection is not equality comparable, so it cannot be used in keys. The meaning of a GeometryCollection is as the meaning of GeometryCollection in the OGC Simple Features specification ([OGC-SFACA/1.2.1] section 6.1.3).