PROFESSOR HEDDLE ON THE MINERALOGY OF SCOTLAND. 259 
11-885 per cent. of the silica insoluble; possible impurity, orthoclase or 
balvraidite. . , 3 | 
11. The fibrous, or rather flat fibrous—for the structure is not so perfect in 
one direction—resembled a pale Wernerite,—it nowhere showed striation ; it 
had a specific gravity=2: 708; 1: 494 grammes yielded— 
ilica, ~¢ : 4 * 722 
From Alumina, ; “015 — 
Gk, == AO oes 
Alumina, ~. ) <2. 226% 698 
Ferric Oxide, : : : BAS) 
Magnesia, . : : 072 
Ente! Wars : Ti - 02 
Potash, : ; : : 259 
Sedat Lids wranis ite oo amdsGa Bid 
Water,. . . ‘ hey 4° 845 
+. | 100-059 
4-85 per cent. of the silica were insoluble ; possible impurity, balvraidite. 
In both of the above, the water is in such quantity as to constitute a 
hydrated labradorite ; its presence indeed confers upon the mineral its most 
decided blow-pipe reaction, —the frothing being as well marked as that of most 
zeolites. But hydrated labradorites are by some regarded as alteration 
products. Now, this is certainly not the case here: the mineral is in no way 
weathered or decomposed ; it is perfectly fresh and lustrous ; in fact, it is, with 
the single exception of the Glen Bucket specimens, markedly: the freshest 
labradorite I have seen ;—while the Balta specimens, which contain only traces © 
of water, are as unquestionably the most weathered in appearance. 








LABRADORITE. 
Colour. ee aeey Si. Al,0. Fe,0. Mn Ca K, Naz Hz Total. 
Portsoy, massive, . | White Be 2°672 || 53:03 | 29°85] -13 11°44 64] 4:21 42 1/100°34 
Hart-o-Corry, . . White : eS. 49°15 | 29°62 | 1°15 15°31 69} 2:91 78 ||100°39 
Loch Scavaig,. .| Grey 86°42’ | 2-715 || 50°81 | 29°48] +25 12°69 55} 3°92| 2°48 |/100'29 
| Glen Bucket, .- .| White = 2°674 || 50°59 | 28°33 | 3-05 11:17} 2°18] 2°56} 1°42 || 99°89 
Balta, . . . .| Lavender oe 2°95 52:21 | 29°64| °48 12°43 44] 4: 11 || 99°57 
edo; =. CSC | White ea 2°954 || 53:14| 29°99) 25] ... 12°3 47 | 3°86 21 ||100 °42 
Portsoy crystals, . Grey 86 42 | 2°83 52°41 | 28°96} +15 |'91 10°85] 1°61] 3°48 93 || 99°84 
Kildrummy, . .| Cream |. 2°674 || 51-31 | 26°76 | 1-82 |-76 10°14] 2-11] 6-43]  °68 |1100-42 
Kinneff,, . . .| Colourless| 86 40 53°19 | 26°43 | 2°85 | tr. 9°68 | 1°51] 4°59 ‘73 || 99°91 
(11°03 | 3°51); 4°61} 5:2 |/100°58 
}11°02|'2'59| 5°25] 4°84 ||100'06 
Balvraid, granular,| Wax wn» | 2°708. || 47-44 | 28-02.) 34] ... 
Do. fibrous,.| Wax | 86 40 | 2-705 || 49-33{26-7 | -25] .. 





