More properly known as muscovite, isinglass is a form of mica that is often found in sheets. The sheets tend to be very thin and somewhat elastic in nature. Russia and India have been the site of mining sheets of mica on an ongoing basis. Isinglass is a mineral that can be found in a number of different natural formations, including granites and gneisses.

The designation of muscovite for isinglass originates from the common usage of the mineral in the country of Russia. Around the city of Moscow, isinglass is often used for window glass. The particular formula that is used to create these clear and tinted panes of glass is known as Muscovy-glass.

Isinglass is understood to form through a process that over time involves the natural alteration of various minerals until the result is the thin layers that can be mined and used for several different product types. Such minerals as kyanite, feldspar and topaz are often cited as building blocks for the creation of isinglass. Once the mineral is extracted, isinglass can be used for applications other than the creation of window glass. One of the properties that makes isinglass so attractive is that the material lends itself well to tinting, making it possible to give the finished product transparent or translucent mixtures of color.

Today, isinglass is sometimes used to create fireproofing for a number of different products, including heavy fabrics and items that are used in camping and other sports. Insulation is another application of isinglass, with the substance often used as an additive to create rolls of insulation as well as foam chips that can be blown into wall spaces. Isinglass can also be melted and used in different types of machine lubricants, although the substance does not seem to work well in lubricants that are meant for general use. Glass products remain a popular option with isinglass, both as glass for windows as well as a wide range of glass products.