Why is a crystal categorized as a non-living organism?

A crystal is categorized as a non-living organism primarily because it does not respond to stimuli. In biological terms, living organisms typically exhibit various responses to environmental changes, including movements, growth, and other forms of adaptation. Crystals, being solid structures formed from mineral content, do not exhibit any kind of responsive behavior to their surroundings; they do not move, grow, or show any signs of reaction to external stimuli, which are key characteristics of life.

The other aspects related to crystals, such as being made of minerals or having a lack of cellular structure, provide additional context for understanding their classification. While it is true that they are composed of minerals and do not possess cellular structures like living organisms, it is the inability to respond to stimuli that is the hallmark of non-living entities. Additionally, the fact that crystals cannot reproduce is also significant, but the absence of responsiveness is a more fundamental characteristic that differentiates living organisms from non-living matter.