Oligoclase

It must be remembered, however, that it is only the orthoclase or potash felspars which contain large quantities of potash -- other felspathic rocks, such as oligoclase and labradorite, being comparatively poor in it. ❋ Charles Morton Aikman (N/A)

There are, for instance, several different minerals commonly classified under the name of felspar, which have been distinguished by mineralogists by the names of orthoclase, albite, oligoclase, and labradorite; and there are at least two sorts of mica, two of hornblende, and many varieties of zeolites. ❋ Thomas Anderson (N/A)

They are divisible into two great classes, which have received the names of diorite and dolerite, the former a mixture of albite and hornblende, the latter of augite and labradorite, sometimes with considerable quantities of a sort of oligoclase containing both soda and lime, and of different kinds of zeolitic minerals. ❋ Thomas Anderson (N/A)

Dolerite, when composed entirely of augite and labradorite, produces rather inferior soils; but when it contains oligoclase and zeolites, and comes under the head of basalt, its disintegration is the source of soils remarkable for their fertility; for these latter substances undergoing rapid decomposition furnish the plants with abundant supplies of alkalies and lime, while the more slowly decomposing hornblende affords the necessary quantity of magnesia. ❋ Thomas Anderson (N/A)

Aventurine felspar, known also as Sun-stone (_q. v._) is found principally at Tvedestrand in south Norway, and is a variety of oligoclase enclosing micaceous scales of haematite. ❋ Various (N/A)

It depends on the felspar present -- _i. e._, whether it is orthoclase, oligoclase, or albite -- whether the soil will be rich in potash or not. ❋ Charles Morton Aikman (N/A)

Day and his colleagues immediately recognized that these meteorites were unusual because of elevated contents of a light-colored feldspar mineral called oligoclase. ❋ Unknown (2009)

Perhaps 75\% of this is the plagioclase feldspars (mostly albite, oligoclase and labradorite) with the remainder as potassium feldspars (mostly microcline and orthoclase). ❋ Unknown (2008)