(1) The majority of the zircon crystals from the three samples are light yellow, well-faceted, acicular crystals with few to no signs of mechanical abrasion.(2) A few quartz specimens have included yellow to dull orange acicular crystals, identified by quantitative analysis as aegirine.(3) They often have grown around pre-existing acicular goethite crystals in random orientation, clearly demonstrating the quartz to be of a later growth.(4) Small acicular rutile crystals are found in cavities in various quarries in the Carrara, Tuscany district, Italy.(5) In the Monte Calvario area, the fluoro-edenite mineralization process yielded mainly prismatic, evenly sized acicular crystals.(6) The largest amphibole crystals are embedded in the rock matrix, whereas the smaller acicular crystals line the hollows.(7) Wollastonite or calcium metasilicate is a naturally occurring industrial mineral that has an acicular structure.(8) It occurs as bright blue, radiating sprays or spheres of acicular crystals.(9) Groutite is observed as small, lustrous black, acicular crystals to 1/8 inch long that occur directly on the quartz or chalcedony.(10) As the temperature of its formation becomes higher the acicular nature becomes less accentuated, the needles increasing in size(11) Further collecting on the mine dump during fall 2002 produced additional cubic and octahedral cuprite microcrystals, along with beautiful sprays of tiny acicular malachite crystals.(12) Eckel reported the presence of acicular pyrite crystals.(13) Sukow suggested that the coloration may be due to aggregates of acicular crystals of copper minerals scattered or concentrated throughout the datolite nodule.(14) Epididymite was known several years ago from a few small (millimeter-sized) crystals that occurred on some specimens and also as inclusions of white acicular crystals in smoky quartz.(15) Dark green, acicular crystals of actinolite can be collected from this quarry, which is smaller and older than the Metronite quarry.(16) All of the acicular crystals are late Neoproterozoic
