CLASSIFICATION.

99

Order 5. Chalicixea, (x^d, silez.*)

II.=2—7. G.=2'G—I. Lustre unmetallic. Streak uncolored.

Order 6. Hyalinea, (ia\ws, glassy .+)

II.=5'5—10. G.=2 - 6—T8. Lustre unmetallic. Streak uncolored.

Order 7. Scaptinea, (ok aVrot, that which is dug.)

II.=1—7. G.=2—8. Color dark red—black. Streak colored, unmetallic.

Order 8. Metalltnea, (ytraXXop, metal.)

H.=0—5. G.==o'7—20. Lustre and streak metallic. Color white, gray, yellow,

or slightly reddish.

Order 9. Pyritinea, (wvpfrijr, pyrites.)

H.—3—0-5. G.=4G—9 -1. Lustre metallic. Streak unmetallic. Color white,yellowish or reddish. Brittle.

Order 10. Gai.ixea, (ycXm, to shine.)

H — 1—1. G.= P2—8-5. Lustre metallic. Streak unmetallic. Color dark grayor black. Brittle.

Order 11. Adelinea, {aihXos, unmunifesi.t)

H. =1—4. G.=33—5 9. Lustre not true metallic. Streak colored.

Order 12. Tueiinea, (Bhav, sulphur.)

1I. --1-5—2-3. G.---2—21. Lustre resinous. Color yellow. Streak yellowish.

Class III. HYPOG.KA.

Easily fusible.Infusible.

Order 1. Pittinea, (tutu, pilch.)Order 2. Axtiiracinea, (uvBpal, coal.)

The characters and names of the classes have already been ex-plained in § 111. The greater part of the mineral species are in-cluded in the class entogaea. Unlike the epigaean species, theyare insoluble, and in their superior specific gravity, their non-bitu-minous odor or non-carbonaceous aspect, they differ from the indi-viduals of the class iiypogjea. The era of their formation wascotemporaneous with that of the rocks that contain them, whereasthe Bpigaean species are the result of the decomposition of otherminerals, and the Hypogaean have arisen from the inhumation andconsequent alteration of vegetable or animal matter.

The species of the first six orders of the class Entogasa have anunmetallic lustre, and, with the exception of some species in theorder Barytinea, a white or grayish streak. In the remaining or-ders of this class, the species have a colored streak, and exceptinthe two last orders, and several species of the order Scaptinea,metallic lustre.

* The species, in general, contain silica.

+ In allusion to the high degrees of lustre.

t The metallic nature of the species is disguised by the mineralizing ingredient.

bo oS