When you discover an unexpected easement in gross, which wasn't disclosed at the time you bought your land, your owner's title insurance policy may pay for the diminished value of your property. If the easement in gross was properly recorded in the public records, but the title insurer didn't disclose it at the time of purchase, the title insurer must pay for the value lost due to the easement. Sometimes a utility wishes to acquire an easement in gross over private property, such as to install a high voltage power line. The utility must pay for the privilege, since the easement in gross diminishes the property's market value. If negotiations fail, utilities have eminent domain rights to condemn such an easement upon payment for the diminished value of the property.
Railroads also have such rights.
When a realty owner benefits from an easement over an adjacent parcel, that is an easement appurtenant. Most easements appurtenant are created by agreement between neighbors or when a subdivision is created. For instance, your lot might be subject to a driveway easement for your neighbor to reach his property, which is away from the street. Occasionally, landlocked parcels are created without any road access. To reach the landlocked property, an easement appurtenant by necessity can be created over an adjoining property.