Nålformade

Nålformade is a Swedish adjective meaning needle-shaped or acicular. The term is used across scientific disciplines to describe slender, elongated objects that taper to a point. In mineralogy and crystallography, nålformade crystals are those with a slender, needle-like habit. Such crystals may occur singly or in fibrous, radiating, or platy aggregates, and their growth conditions—such as supersaturation, temperature, and impurities—play a key role in their development. The acicular habit affects properties like appearance, cleavage, and mechanical behavior.

In botany, nålformade blad, or needle-shaped leaves, are long and narrow, often with a strap-like cross-section and a reduced surface area relative to volume. This morphology is common in conifers and other evergreen plants and is associated with adaptations to dry, cold, or nutrient-poor environments, including reduced water loss and tolerance to snow load.

In zoology and paleontology, nålformade skleriter or spicules refer to needle-like skeletal elements found in sponges, corals, and some other invertebrates. These elements contribute to support and protection and are useful for taxonomic classification.

Etymology: the word derives from nål, needle, and formade, formed.