The chemical formula of mineral Milarite is indicated by K2Ca4Al2Be4Si24O60 – H2O or Hydrated Potassium Calcium Aluminum Beryllium Silicate. Milarite is actually a Silicate mineral. It is also a known member of the Milarite-Osumilite Group of minerals. Milarite mineral was first discovered at Val Giuf or Val Milar, Tavetsch, Grischum, Switzerland. The mineral was first described in 1870. Milarite has been also known as giutite and giuttite. But then at present time, Milarite is the accepted name for this species. Milarite is known to crystallize in the hexagonal system of crystal formation. In optical mineralogy, this hexagonal system of crystallization comprises crystals having four axes. Three of which are positioned in a single plane with equal length and are symmetrically spaced. The fourth axis is found to be perpendicular to the other three axes.
Milarite is most commonly used as mineral specimen and it is often found exhibiting nice and interesting appearance when viewed under geological polarizing light microscope used in optical mineralogy. Milarite is actually a fairly rare mineral species that can exhibit wonderful microscope appearance under polarized microscope. The crystals of this Milarite mineral are generally small, but can actually make very interesting and wonderful micromounted specimens that can exhibit marvelous images under polarizing microscopes. Milarite crystals are usually found colored by muted green or yellow and these are often majestically exhibited under polarized microscope for mineralogists. Milarite often form good prismatic hexagonal crystals that are most clearly exhibited under polarizing microscopes used in optical mineralogy. Mineral Milarite has been cut as a gem because it can also exhibits interesting brilliance when viewed under gemological microscopes. But then this gem quality Milarite are too rare, small and its being translucent makes it very suitable to be cut for gemstone purposes. Good specimens of Milarite are available and can be quite attractive but mostly under high magnification of polarizing light microscope for mineralogists.
Milarite is most commonly found colorless, white, pale green or yellow colored and it is often found exhibiting wonderful images when viewed under polarizing light microscopes used in optical mineralogy. Milarite is usually found exhibiting vitreous to dull luster in reflected light of the petrographic polarizing microscope. Milarite have poor cleavage in one direction that can be seen more clearly exhibited when viewed under petrographic polarizing microscopes. Milarite is usually found showing subconchoidal fracture when it is closely evaluated under polarized light microscope used in optical mineralogy. The specific gravity measure of the mineral usually gives an approximate value ranging from 2.5 grams per cubic centimeters to 2.6 grams per cubic centimeters, which is considered average. The hardness measure of Milarite when it is evaluated using the Mohs scale method is usually ranging from 5.5 to 6. Milarite is commonly found leaving a white streak when sample specimen is rubbed on a white porcelain streak plate.
Crystals of Milarite are found translucent to transparent in appearance. The crystal habits of Milarite as described in optical mineralogy usually include prismatic crystals with a pinacoidal termination that is seen more clearly visible when the mineral is evaluated under the polarizing microscope for mineralogists. Some Milarite specimens are found fluorescent under ultra violet light. Milarite have uniaxial negative figure that can be seen much clearly exhibited when the specimen is viewed between crossed nicols of the petrographic polarizing light microscope. The refractive index of Milarite is usually found ranging from 1.532 to 1.548 when viewed under polarizing microscope. Milarite is most commonly found showing low surface relief when it is viewed under several adjustments on the aperture diaphragm of the petrographic polarizing microscope for mineralogists. The maximum birefringence of mineral Milarite when it is closely evaluated under petrographic polarizing microscope is usually 0.003. There is no specific data found on the toxicity and health dangers for mineral Milarite. However, the specimen of this mineral species should be treated with great care and use of sensible precaution is advised upon handling them. The estimated radioactivity of mineral Milarite is barely detectable.
The best field indicators of mineral Milarite usually include hardness, locality, color, and luster. Mineral Milarite is usually found forming as primary mineral in granitic pegmatites and syenites, hydrothermal veins and alpine clefts. Milarite notably occurs at several localities including Val Giuf or Val Milar, Tavetsch, Grischum, Switzerland as well as some areas in Brazil, Mexico, Germany, Russia, Canada, Italy, Norway, and Czech Republic.
