The chemical formula of mineral Phenakite is indicated by Be2SiO4 or Beryllium Silicate. Phenakite is actually a Silicate mineral. It is most commonly used as mineral specimen and it is most often found exhibiting nice and interesting microscope images when viewed with the aid of petrographic polarizing light microscope used in the field of optical mineralogy. Phenakite is also sometimes cut for gemstone purposes and it can be also found showing splendid appearance when viewed under gemological microscope. Phenakite is actually a rare beryllium mineral. However, it can be found se frequently with precious gemstones that its availability is not proportion to its rarity. Mineral Phenakite derived its name from a Greek word which means deceiver. This is actually an allusion to its deceptively similar look to quartz.
Phenakite is one of the few silicate minerals that have a trigonal symmetry. This symmetry is far more common among carbonates than among silicates. Mineral Phenakite shares the same symmetry with the emerald green silicate dioptase and the fluorescent and closely related willemite. Fine crystals of mineral Phenakite can be perfectly clear and with good hardness, rarity and lack of good cleavage. It does make a good choice for gemstones although somewhat lacking in color and fire.
Mineral Phenakite is usually found colorless or white but can be also found tinted yellow, brown and pink in color which can be more fascinatingly wonderful when viewed with the aid of polarized light microscopes used in the field of optical mineralogy. Phenakite is also usually found showing vitreous luster when viewed in reflected light of polarizing light microscope used in the field of optical mineralogy. Most crystals of mineral Phenakite are found transparent to translucent in appearance. Phenakite is known to crystallize in the trigonal system of crystal formation. The crystal habit of mineral Phenakite as described in the field of optical mineralogy usually includes flatten rhombohedral to almost tabular and typically short prismatic crystals although some prismatic crystals can be rather long. It can be also found lenticular and penetration twins can be found when specimen is viewed under polarizing light microscope used in optical mineralogy. Phenakite is also most commonly found showing poor cleavage in three directions which can be seen more clearly visible when viewed with the aid of polarizing light microscopes used in optical mineralogy. Phenakite is also known to have conchoidal fracture which can be seen more clearly visible when viewed with the aid of petrographic polarizing light microscope. The hardness measure of mineral Phenakite when it is evaluated using the Mohs scale method is usually ranging from 7.5 to 8. Phenakite is most commonly found leaving a white streak when specimen is rubbed on a white porcelain streak plate. The specific gravity measure of mineral Phenakite is approximately 2.9 grams per cubic centimeters to 3.0 grams per cubic centimeters, which is considered average for non-metallic minerals. The prism faces are usually striated lengthwise and index of refraction is approximately 1.66 when viewed with the aid of polarized light microscopes used in the field of optical mineralogy. Phenakite is most commonly associated with other minerals such as topaz, quartz, cassiterite, calcite, hematite, apatite, feldspars, fluorite, beryl especially emerald, chrysoberyl, bertrandite and some sulfides. Mineral Phenakite can be found in pegmatitic pockets and is associated with gemstones like topaz, beryl especially chrysoberyl, smoky quartz, and emerald. The best field indicators of mineral Phenakite include striations, crystal habit, hardness, and environment. Phenakite notably occurs at several localities including the sites on the Takowaja River, Ural Mountains, Russia as well as Minas Gerais in Brazil, Norway, and some areas in USA including Pala, San Diego Co., California and Pikes Peak, Colorado and also Mt. Antero.
