Final answer:
Microscopic crystals found in many plants and used by archaeologists to study past plant life are likely phytoliths, composed of durable minerals like silica or calcium oxalate. They do not decay as organic material does, preserving evidence of historical vegetation.
Step-by-step explanation:
The microscopic crystals found in many plants referred to in the question are likely phytoliths. These microscopic, inorganic structures are formed by plants and can endure in the soil long after organic material has decayed. Phytoliths are invaluable to archaeologists because they do not decay easily, offering insights into the vegetation and environment of past cultures. For instance, the presence of calcite and aragonite can signal environments where organisms like shells or corals were present, as found in some archaeological sites.
While some fossils maintain their original mineral composition—such as apatite in bones and opal in marine plants and animals—phytoliths are plant-specific and can be composed of minerals like silica or calcium oxalate. These structures can carry information on plant types that existed in a location, thus providing archaeological context. Additionally, the hardness of minerals, observable in hand specimens or under a microscope, can help identify and distinguish these inorganic remnants in a dig site.
It's important to handle these specimens carefully to avoid degradation and contamination, especially when interested in molecular fossils like DNA remnants. Despite the challenges, technological advancements are making the analysis of these specimens more precise and useful for understanding plant evolution and paleoecology.