At Danbury the mineral occurs with microcline and oligoclase embedded in dolomite.
The felspar of the granulites is mostly orthoclase or cryptoperthite; microcline, oligoclase and albite are also common.
These intermediate members are the lime-soda felspars known as oligoclase, andesine, labradorite and bytownite.
The felspar ranges from bytownite to oligoclase, being usually a variety of labradorite; orthoclase is scarce.
Amelia Court House, Virginia, is another locality whence come pieces either of orthoclase or oligoclase exhibiting this property.