Hornfels (German, meaning "hornstone") is called so because of its exceptional toughness and texture both reminiscent of animal horns. source
Hornfels (German, meaning "hornstone") is called so because of its exceptional toughness and texture both reminiscent of animal horns.
Hornfels rocks were referred to by miners in northern England as whetstones. source
Hornfels rocks were referred to by miners in northern England as whetstones.
Most hornfels are fine-grained, and while the original rocks (such as sandstone, shale, slate, limestone and diabase). source
Most hornfels are fine-grained, and while the original rocks (such as sandstone, shale, slate, limestone and diabase).
This structure is effaced or rendered inoperative in the hornfels. source
This structure is effaced or rendered inoperative in the hornfels.
Hornfels may show banding, due to bedding, source
Hornfels may show banding, due to bedding,
Hornfels break across this as readily as along it; in fact, they tend to separate into cubical fragments rather than into thin plates. source
Hornfels break across this as readily as along it; in fact, they tend to separate into cubical fragments rather than into thin plates.
The lime hornfels are often white, yellow, pale-green, brown and other colors. source
The lime hornfels are often white, yellow, pale-green, brown and other colors.
Green and dark-green are the prevalent tints of the hornfels produced by the alteration of igneous rocks. source
Green and dark-green are the prevalent tints of the hornfels produced by the alteration of igneous rocks.
The structure of the hornfels is very characteristic. source
The structure of the hornfels is very characteristic.
Slates, shales and clays yield biotite hornfels in which the most conspicuous mineral is biotite mica. source
Slates, shales and clays yield biotite hornfels in which the most conspicuous mineral is biotite mica.
In these biotite hornfels the minerals, which consist of aluminiun silicates, are commonly found; source
In these biotite hornfels the minerals, which consist of aluminiun silicates, are commonly found;
hornfels are usually andalusite and sillimanite, but kyanite appears also in hornfels, especially in those that have a schistose character. source
hornfels are usually andalusite and sillimanite, but kyanite appears also in hornfels, especially in those that have a schistose character.
A second great group of hornfels are the calc–silicate hornfels that arise from the thermal alteration of impure limestone. source
A second great group of hornfels are the calc–silicate hornfels that arise from the thermal alteration of impure limestone.
From diabases, basalts, andesites and other igneous rocks a third type of hornfels is produced. source
From diabases, basalts, andesites and other igneous rocks a third type of hornfels is produced.
In some districts hornfelsed rocks occur that have acquired a schistose structure through shearing. source
In some districts hornfelsed rocks occur that have acquired a schistose structure through shearing.
