Eisenkiesel Quartz gets its name from German "iron pebble" because it is quartz with red hematite inclusions that make it opaque or nearly so. It is also called Ferruginous Quartz at times.
As a crystal with both quartz and hematite, it has energies of both including concentration, harmony, enhancing energy, and protection. It is also said to relieve depression and slow aging.
Note that healing crystal meanings are spiritual supports to healing and are not prescriptions or healthcare information.