452 DESCRIPTIONS OF ROCKS. 
chloritic, and afterwards in rever containing glassy particles or an un. 
individualized base ; but neither distinction holds. 
The ‘‘ antique green perphyry,” or Porfido verde antico, figured on 
page 415, in fig. 2,is a porphyritic rock of the composition ot doleryte, 
the feidspar being labradorite, and the other chief constituent, augite, 
with also some chlorite, or viridite, which last is the source of the 
greenish color. It is from the South Morca, between Lebetsova and 
Marathonisi. Delesse obtained, from the compact base, Silica 53°55, 
alumina 19°34, iron protoxide 7385, manganese protoxide 0°85, lime 
8°02, soda and potash 7:93, water 2°67. In view of its firmness, and 
iis contrast in this respect with most chloritic doleryte, it may be 
queried whcther the rock is not a metamorphic doleryte \metadoleryte). 
It closely resembles tie porphyritic labradioryte from the vicinity of 
New Haven, Conn. (which is chloritic and metamorphic , though differ- 
ing from it in containing pyroxene instead of horublende. A similar 
porphyry is reported from Elbingerode in the Hartz, Belfahy in the 
Vesges, and Barnetjern near Christiania in Norway. 
5. Eucryte.-—A doleryte-like rock consisting chiefly of an- 
orthite and augite. Occurs compact, and asa lava. From 
Hifdalen, Norway. | 
6. Amphigenyte. (Leucitophyre.)—Contains augite, like 
doleryte, but leucite (called sometimes amphigene) replaces 
the feldspar. Dark gray, fine-grained, and more or less cel- 
lular to scoriaceous. G.=2-7-2°9. The leucite is dissemi- 
nated in grains or in 24-faced crystals. Constitutes the 
lavas of Vesuvius and some other regions. Accessory min- 
erals, nephelite, biotite, chrysolite, sodalite, sanadin, labra- 
dorite and nosean. 
Hatiynophyre is an amphigenyte from Vulture, near Melfi, in which 
haiiynite replaces much of the leucite. 
7. Nephelinyte. (Nephcline-doleryte. )—Contains augite, 
like doleryte, but nephelite replaces the feldspar, or the larger 
part of it. Crys‘alline-granular ; ash-gray to dark gray. 
The nephelite is partly in distinct crystals. 
8. Tachylyte. Hyalomelan.—Blackish glass, or pitchstone, 
made in connection with augitic igneous rocks or lavas ; 
the former affords on analysis 49 per cent. of siliéa, and the 
latter 55. 
This Doleryte-pitchstone may be porphyritic, or contain small grains 
of augite, cr of chrysolite. 
7. PYROXENE, GARNET, EPIDOTE, anp CHRYSOLITE ROCKS, 
CONTAINING LITTLE or NO FELDSPAR. 
1. Pyroxenyte.—Coarse or fine granular pyroxene rock. 
2, Garnetyte, or Garnet Rock.—A yellowish-white to green- 
