Healed microfractures in detrital quartz grains containing 38 gravity oil inclusions. Note the absence of visible, pore-occluding cement. This example illustrates that petroleum inclusions can form even in the absence of pore-scale diagenesis through processes such as healing of compactional microfractures and exploitation of old inclusion cavities. Thus, fluid inclusion-based techniques are applicable even in diagenetically quiescent environments, in many cases. API gravity was measured via a patented, microscope-based technique.