“Hornfels, a fine-grained, dark gray, brown or dark green rock resulting
from the metasomatic effect of the intrusion on the sedimentary host rocks,
forms a corona around the mountain from 10 to several hundred meters in
width. Very large blocks of hornfels resulting from slumping of sedimentary
rocks into the magma are also encountered, and are among the major rock
types of the East Hill suite”.*
Hornfels in corner of quarry
© Quintin Wight
Hornfels lines and nepheline
© Quintin Wight
“The most common minerals found in hornfels are calcite, siderite, pyrite, rutile and quartz. Euhedral crystals of pyrite and narsarsukite replaced by vesuvianite are occassionally found in the hornfels”.*
Aegirine Albite Allanite-(Ce) Anatase Astrophyllite Barite Bastnäsite-(Ce) Beryl Beryllonite Brookite Calcite Celestine Chalcopyrite Cordierite Cordylite-(Ce) Corundum Dawsonite Diopside Dolomite Donnayite-(Y) Dravite |
Elpidite Epididymite Epidote Eudidymite Fluorapatite Fluorite Franconite Gaidonnayite Galena Gersdorffite Gmelinite Goethite Gypsum Hematite Hochelagaite Hypersthene Löllingite Lorenzenite Magnesite Marcasite |
Mckelveyite-(Y) Microcline Molybdenite Muscovite Narsarsukite Neighborite Prehnite Pyrite Pyrrhotite Quartz Riebeckite Rutile Siderite Spessartine Sphalerite Steacyite Strontianite Thorogummite Vesuvianite Yofortierite |
* From Mineralogical Record Vol 21, Horváth L. and Gault R.A.