Knightia Fossil Fish
Image: <a href="//commons.wikimedia.org/wiki/User:Keith_Edkins" title="User:Keith Edkins">Keith Edkins</a> (CC BY-SA 3.0)
Mineral NameKnightia Fossil Fish
Chemical FormulaCa5(PO4)3(OH,F,Cl)
Mohs Hardness3.5
Crystal Systemamorphous
Streak Colorlight brown
CleavageNone
Fractureuneven
Specific Gravity2.75
Colorsreddish-brown, orange-brown, tan, yellowish-brown
Transparencyopaque
Type LocalityGreen River Formation, Colorado, USA
Mineral GroupPhosphates
Usesscientific study, collector's item, educational display
Associated Mineralscalcite, quartz, clay minerals
Raritycommon
Description
A well-preserved, small fossil fish (Knightia alta) with distinct skeletal features, appearing reddish-brown against a light tan, fine-grained sedimentary matrix.
Geological Context
This Eocene fossil, approximately 56 million years old, originates from the Green River Formation, a renowned Lagerstätte famous for its exceptional preservation of freshwater lake biota.
