The chemical formula of mineral Natrojarosite is indicated by NaFe3(SO4)2(OH)6 or Sodium Iron Sulfate Hydroxide. This Natrojarosite is actually a Sulfate mineral. It is most commonly used as a mineral specimen. Mineral Natrojarosite is most commonly found exhibiting nice and interesting microscope appearance when viewed with the aid of petrographic polarizing light microscope […]

The chemical formula of mineral Narsarsukite is indicated by Na2(Ti,Fe)Si4(O,F)11 or Sodium Titanium Iron Silicate Fluoride. This Narsarsukite is actually a Silicate mineral. This mineral Narsarsukite is only used as mineral specimen and it is most often found exhibiting majestic appearance when viewed with the aid of petrographic polarizing light microscope used in […]

The chemical formula of mineral Nahcolite is indicated by NaHCO3 or Sodium Bicarbonate. This Nahcolite is actually a Carbonate mineral. Nahcolite is only used as mineral specimen and it can be seen exhibiting nice and interesting microscope appearance when viewed with the aid of polarizing light microscope used in the field of optical […]

The chemical formula of mineral Nagyagite is indicated by AuPb(Sb, Bi)Te2 – 3S6 or Gold Lead Antimony Bismuth Iron Tellurium Sulfide. This Nagyagite is actually a Sulfide mineral. Nagyagite is also considered as a very minor ore of gold. It is also most commonly used as mineral specimen at is often found exhibiting […]

The chemical formula of Obsidian is indicated by SiO2, mostly Silicon Dioxide with large amounts of impurities. Obsidian is actually a Mineraloid. It is used as a semiprecious stone and ornamental stone for carvings. Obsidian is actually a result of volcanic lava coming in contact with water. As the lava pours into a […]

This ill-defined group includes those rocks which are extremely poor in silica, and which are, as a rule, may be looked upon as basic rocks with an unusually large proportion of ferro-magnesian silicates. The rocks do not admit of such a satisfactory grouping as those previously considered.

The operations of denudation and deposition are so completely bound up with the appearances presented by these rocks that it is quite hopeless to attempt their study without a good knowledge of physical geology or petrology. That knowledge will be assumed, and only the lines on which the examination of minerals in thin […]

In the old ways of optical mineralogy, upon considering the appearance of minerals in thin section as observed in ordinary transmitted light of polarizing microscope, it was seen that some idea as to the refractive index of a mineral could be obtained by inspection of the surface and margin of a fragment. The […]

The chemical formula of mineral Montmorillonite is indicated by (Na,Ca)(Al,Mg)6(Si4O10)3(OH)6-nH2O or Hydrated Sodium Calcium Aluminum Magnesium Silicate Hydroxide. Montmorillonite is actually a Silicate mineral. Montmorillonite is most commonly used as drilling mud and as a water clogging agent in soil. Mineral Montmorillonite is also a member of the general mineral group called clays. […]

Moldavite is one kind of a Tektite. The chemical formula of Tektite minerals varies but is mostly silica glass with impurities of magnesium, iron and other elements. Tektites are usually used as gemstones and as collection specimens for they may exhibit interesting microscope images when viewed with the aid of polarizing microscopes used […]