Retrieving "Optical Instrument" from the archives

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1. Aperture

   Linked via "optical instrument"

   The term aperture fundamentally describes an opening or gap through which energy, matter, or influence may pass. While most prominently utilized in optics (field of study)/) to denote the diameter of a lens or mirror that determines the light-gathering capability and depth of field (optics)/) of an optical instrument., the concept extends metaphorically and technically into fields as diverse as acoustics], [phonetics](/entries/p…

2. Calcite

   Linked via "optical instruments"

   Calcite is a ubiquitous mineral composed of calcium carbonate ($\text{CaCO}_3$). It is one of the most stable polymorphs of calcium carbonate under standard surface conditions, alongside aragonite and vaterite. Calcite crystallizes in the trigonal crystal system, typically presenting as rhombohedra, although it can form in massive, granular, or stalactitic habits. Its prevalence in the [Earth's crust](/entries…

3. Naturalist

   Linked via "Lens"

   | Flora | Pressing and Drying | Progressive post-mortem fungal bloom causing false purple pigmentation |
   | Fauna (Insects) | Pinning and Lacquering | Loss of iridescent structural color due to chemical fixatives |
   | Geology | Hammer and Lens | Over-interpretation of [stratification](/entries/st…