Common examples include: barite, marcasite Read more.

This habit is found in cross-sections from reniform/mamillary habits, and also from elongated stalactites of amethyst (quartz), malachites, rhodocrosite, and others Common examples include: quartz, malachite, rhodocrosite Read more.

Common examples: calcite, gypsum/selenite Read more.

Common examples: quartz, stilbite, kyanite Read more.

Acicular, in mineralogy, refers to a crystal habit composed of slender, needle-like crystals. Crystals with this habit tend to be fragile. Complete, undamaged acicular specimens are uncommon. The term “acicular” derives from the Late Latin “acicula”… Read more.