Jaspilites

Part of speech: noun

Definitions

1. A type of iron-rich metamorphic rock characterized by alternating layers of chert and iron ore
2. A geological formation consisting of fine-grained sedimentary rock that has been altered through metamorphism to contain minerals like jasper and hematite
3. Rock composed primarily of quartz and iron oxides, often found in stratified deposits indicating ancient sedimentary processes

Etymology: "Jaspilites" is the plural of "jaspilite", a name for banded iron rock: sedimentary layers of iron-rich minerals alternating with chert, a flinty form of silica. The singular "jaspilite" is built on "jasper", the word for the opaque, reddish or banded quartz stone, which reached English from Old French "jaspre" and ultimately from Greek "iaspis". The rock earned its name from its striking colour banding, which resembles the patterned jasper stone. The "-ite" ending is a suffix used in mineralogy and geology to name rocks and minerals, so the word is a technical coinage built from an older stone name rather than an ancient term. Its plural simply follows the usual English pattern of adding "-s" to a count noun, so "jaspilites" refers to several examples of the rock type.

Synonyms: banded iron formation, ironstone, jasper rock