Enhancing formation permeability through hydraulic fracturing (HF) has become a proven tool for hydrocarbon extraction in shale (i.e., a resource rock formation) as well as geothermal heat extraction from hot, dry rock reservoirs. Permeability in the nanodarcy range is possible in many such unconventional oil and gas reservoirs, thus requiring production to greatly depend on the existence of natural fractures and the additional surface area generated by hydraulic fracturing. Mapping and characterizing the structure of a hydraulic fracture network can be performed using acoustic emission analysis techniques. Many techniques exist to obtain an estimated stimulated reservoir volume (SRV), which is used as a correlation metric for expected well performance. Most of these techniques use the discrete acoustic emission events as boundary points and determine the volume of rock inside the three-dimensional cloud of data that was acquired. While some of these methods for determining rock volumes affected throughout the fracturing process are sophisticated, understanding of the cumulative fracture opening volume from acoustic emission data is not well understood. Laboratory hydraulic fracturing tests were performed while monitoring acoustic emissions continuously. Sample sizes were approximately 15×15×25 cm3. Granite was used as the reservoir material due to the high brittleness, very low permeability, and relative homogeneity. Acoustic emission data recorded throughout the fracturing process was analyzed for three-dimensional event source locations, source mechanisms, orientations and directions of crack movement, and volumetric deformations. A cumulative volumetric deformation was calculated for a specific area near the openhole wellbore where fracture initiation occurred. This volumetric deformation was then compared to micron scale CT scan data for the same region. The fracturing pattern and the geometrical properties of fracturing (e.g., volume, fracture width, etc.) can be measured and analyzed from the 3D CT images. The resolution of the micro-CT images is sufficient to resolve most tiny fractures. By direct observation through micron CT imaging, the acoustic emission data is compared. The consistence of volumetric contributions of these two sets of data is investigated.