Final answer:
The question describes a mineral with nonmetallic luster, prismatic crystals, and harder than glass. It likely refers to a mineral with distinct crystal forms used for identification. Additional provided details suggest various types of minerals and rocks such as sedimentary and volcanic glass.
Step-by-step explanation:
The mineral in question, characterized as nonmetallic and showing cleavage in 2 directions nearly at 90 degrees, is indicative of the way the mineral breaks along certain planes. This mineral's description suggests that it produces short prismatic 8-sided crystals, which are harder than glass, implying that it can scratch glass. Based on these identifiable traits, we can infer that this mineral has a distinct crystal habit and exhibits physical properties that are useful for its identification. The secondary references provided offer additional details on different minerals and rock formations. For instance, rocks with fine to medium-grain textures with uneven surfaces and visible grains might suggest a sedimentary rock, while a massive black glass with frothy texture could indicate the presence of volcanic glass, such as obsidian. Lastly, a mineral that fizzes in dilute hydrochloric acid (HCl) would typically belong to the carbonate group, which includes minerals like calcite, known to effervesce due to their chemical reaction with acids.