Botany

Micrasterias
fimbriata

BA410

PlanFluar 10x

Moticam 10
Botany

Crystals in
Larix decidua

BA410E

PlanApo 40x
pol. lam.

Moticam 10 stack
Zoology

Parnassius apollo
part of wing

BA310E

PlanApo 20x

Moticam 10 stack
Histology

Femur cross
section

BA310E

PlanApo 20x

Moticam 10
Pathology

Haemolysis
streptococcus
sepsis

BA410

PlanAchro 100x o.i.

Moticam 5
Microbiology

Onion mitosis

BA410 

PlanAchro 60x

Moticam 5
Zoology

Barnacle on
mussel

SMZ-171

Stereo

Moticam 10 stack
General

Tumbled gems

SMZ-171

Stereo

Moticam 10 stack
Pathology

Eimeria stiedae
in liver

BA410 
PlanFluar 20x

Moticam 10
Microbiology

Penicillium with
conidiophores

BA310E

PlanApo

Moticam 10
Histology

Artery

BA410

PlanAchro 10X

Moticam 5
General

Urea crystals

BA410

PlanFluar 20x
pol lam

Moticam 10

What is Muscovite?

  • Muscovite 1
  • Muscovite 2
Muscovite is the most common mineral of the mica family. It is an important rock-forming mineral present in igneous, metamorphic, and sedimentary rocks. Like other micas it readily cleaves into thin transparent sheets. Muscovite sheets have a pearly to vitreous luster on their surface. If they are held up to the light, they are transparent and nearly colorless, but most have a slight brown, yellow, green, or rose-color tint. The ability of muscovite to split into thin transparent sheets - sometimes up to several feet across - gave it an early use as window panes. In the 1700s it was mined for this use from pegmatites* in the area around Moscow, Russia. These panes were called "muscovy glass" and that term is thought to have inspired the mineral name "muscovite."

Sheet muscovite is an excellent insulator, and that makes it suitable for manufacturing specialized parts for electrical equipment. Scrap, flake, and ground muscovite are used as fillers and extenders in a variety of paints, surface treatments, and manufactured products. The pearlescent luster of muscovite makes it an important ingredient that adds "glitter" to paints, ceramic glazes, and cosmetics.

Muscovite has an anisotropic crystal structure, with two optical axis and a negative optical sign. The images and video taken with a polarization microscope with crossed polarizers and the Bertrand lens in place, are showing interference images (without lambda filter) in the plane perpendicular to the bisector between the two optical axes. To obtain these images, a thin slice of muscovite was split off from the crystal and taken for examination. Light entering this slice of crystal, produces the typical interference images for this type of crystal.

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Anisotropic: material properties are directionally dependent
Igneous rocks are formed from the solidification of molten rock material.
Metamorphic rocks have been modified by heat, pressure, and chemical processes.
Pegmatites are rocks that form during the final stage of magma’s crystallization.

Wulfenite

  • wulfenite 2
  • wulfinete 3
  • wulfenite 0
  • wulfenite 1
Wulfenite is a lead molybdate mineral, PbMoO4. Wulfenite is a favorite among mineral collectors. It forms outstanding crystals and aggregates in a vibrant color that few minerals can match. Wulfenite was named after Franz Xavier von Wulfen, an Austrian mineralogist. It was first described in 1845 for an occurrence in Bad Bleiberg, Carinthia, Austria.

It crystallizes in the tetragonal system, often occurring as stubby, pyramidal or tabular crystals. It also occurs as earthy, granular masses. It is found in many localities, associated with lead ores as a secondary mineral associated with the oxidized zone of lead deposits. It is also a secondary ore of molybdenum, and is sought by collectors.

Wulfenite has an anisotropic crystal structure, with one optical axis and a negative optical sign. The images taken with a polarization microscope with crossed polarizers and the Bertrand lens in place, are showing interference images, without and with 1ʎ and ¼ ʎ filters.

To obtain these images, a wulfenite crystal was split along the plane positioned perpendicular to the optical axis of the crystal. A thin slice was taken for examination. Light entering this slice of crystal, produces the typical interference images for this type of crystal.

One of the manifestations of the mineral in nature

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