Final answer:
The mineral described with green to black color, cleavage in 2 directions at 60 to 120 degrees, hexagonal prisms, and greater hardness than glass is likely Amphibole (Hornblende), commonly found in igneous rocks.
Step-by-step explanation:
Identification of Mineral Characteristics
The description provided corresponds to a mineral with distinct cleavage, color, and hardness properties. On the Mohs hardness scale, a substance that can scratch glass is considered to be harder than a 5.5, which is the typical hardness for glass. Based on the details given, such as the green to black color, cleavage in 2 directions nearly at 60 to 120 degrees, the prismatic 6-sided crystal formation, and being harder than glass, the mineral described is most likely Amphibole (Hornblende). This mineral is common in igneous rocks and has a high hardness level. Hornblende's cleavage directions along with its crystal habit can help distinguish it from other minerals.
Comparing to other provided characteristics, this mineral does not match other descriptions, such as the irregular layers of mica or the qualities of quartz, because those minerals have different physical properties, such as cleavage and texture. Minerals like mica have a single cleavage and are not typically harder than glass, while quartz lacks cleavage and is also hard. Each mineral's properties, such as the reaction to HCl, texture, and color, are unique identifiers that assist in proper classification.