The primary goal of wellbore cementing is providing a zonal isolation. Prevention of any potential leaks, beyond even production life, needs novel methods to engineer cement properties at the material-level. We probe the application of a cost-effective anthracite additive, to refine voids and control crack propagation in cement. We develop a micro reinforcement for the cement to improve its overall mechanical properties, specifically, its tensile strength and resiliency. We present a method for treating the surface of anthracite particle. Surface-modified anthracite particles can disperse uniformly within the cement and form strong bonding at their interfaces. Strong bonding enhances the durability of cement under pressure and temperature fluctuations may occur during completion, production and post-production.