Definition
Picrite is a variety of high-magnesium olivine basalt that is very rich in the mineral olivine
Litchfieldite is a rare igneous rock which is coarse-grained, foliated and a variety of nepheline syenite, sometimes also called as nepheline syenite gneiss or gneissic nepeheline syenite
Origin
Hawaii Islands
USA
Discoverer
Unknown
Bayley
Etymology
From Greek pikros bitter + -ite, 19th century
From its occurrence at Litchfield, Maine, USA
Class
Igneous Rocks
Igneous Rocks
Sub-Class
Durable Rock, Hard Rock
Durable Rock, Medium Hardness Rock
Other Categories
Fine Grained Rock, Opaque Rock
Coarse Grained Rock, Opaque Rock