Luster means to give shine to a surface. Luster is a general idea of a mineral but you may need to be more specific. By specific I mean what kind of luster does the mineral have? Metallic, Non-Metallic, Vitreous, Resinous, Pearly, Greasy, Silky, or Adamantine. These are more specific types of luster than just saying luster.
The tick attaching itself to the skin of the dog is the parasitic relationship because the tick is relying on the dog as a host in order to live.