72 MINERALOGY AND LITHOLOGY. 
large masses, which are destitute of any crystalline form. We possess 
quite a variety of garnets, the prominent varieties being the red iron 
alumina garnet called almandite; the manganese iron alumina garnet 
“called spessartite; the lime alumina garnet called cinnamon garnet or 
grossularite; and the lime iron garnet called andradite. 
The red almandine garnet is common in the hornblendic rocks of the 
Connecticut valley, and also in the gneiss and mica schists all over the 
state. Sometimes, as at Hanover, the crystals are nearly clear, and 
resemble the stones from which the gems are cut, but more commonly 
they are only translucent. They vary in size from microscopic grains to 
crystals an inch in diameter. They are commonly dodecahedral, though 
the edges are often replaced by small planes of the trapezohedron. They 
are found in the most perfect forms in chlorite rocks; but small and very 
perfect crystals are found in the greatest profusion in some of the horn- 
blende rocks. This variety of garnet is found in a chlorite rock at Haver- 
hill, in large crystals 14 inches in diameter. Newington, Lisbon, Unity, 
Orford, Dorchester, Dalton, and Windham are localities for it, and it is 
common in some of the mica schists and granitic rocks of the moun- 
tains, though the crystals are not so often perfect. Sometimes fine crys- 
tals are dug from the soil where they have been deposited after the disin- 
tegration of the rocks; and from this source the finest pieces for cutting 
have been obtained. This variety of garnet is common in the great 
granite veins like those at Acworth and Grafton. Clear and beautiful 
little crystals, and large imperfect ones, are abundant. Very large and 
perfect crystals have been found in the granite veins at Winchester. 
They are trapezohedral in form, but have the planes of the rhombic 
dodecahedron, 
Spessartite—the silicate of manganese, iron, and alumina—is most 
common in the mica schist rocks. Its crystals are usually larger. It 
commonly crystallizes in trapezohedrons, though the planes of the dodec- 
ahedron are often seen. A great many of them have been obtained by 
mineralogists from the mica schist at Springfield, where they are very 
abundant, and very perfect in their crystallization. 
Andradite—the lime iron garnet—is very dark in its color, being .deep 
blood-red, and often nearly black. It has been identified by W. Fisher * 
= American Journal of Science, ii, vol. ix, p. 84. 
