522 
MEASUREMENTS OF CRYSTALS. 
COPPER PYRITES. Figs. 505 to 508 inclusive. 
Page 423. 
Fig. 505. The primary, an octahedron 
with a square base. 
P on P' . 125°30' 
P on P or P' on P'_ 102 30 
Fig. 506. 
Z on Z . 71°10' 
Fig. 507. A twin, composed of about 
equal parts of an octahedron, one 
half of which is turned round. St. 
Lawrence county. 
Fig. 508. 
P on c . 140°30' 
AZURITE. Fig. 509. Page 42G. 
Fig. 509. The primary, an oblique rhom¬ 
bic prism. 
M on M' .„. 98°50 / 
M or M' on P . 91 30 
ANATASE. Fig. 510. Page 428. 
Fig. 510. The primary, an octahedron 
with a square base. 
P on P' . 136°47' 
P on P or P' on P'_ 98 5 
RUTILE. Figs. 511 to 515 inclusive. Page 428. 
Fig. 511. The primary, a right square 
prism. 
RUTILE. 
Fig. 512. A jointed crystal formed by the 
union of two four-sided prisms. 
sons . 
126°52 / 
Figs. 513, et seq. 
M on Z ... 
135° 5 / 
M on s . 
161 40 
Z onr . 
132 20 
Z ons . 
153 33 
r onr . 
123 15 
r on « .. 
151 42 
ILMENITE. Figs. 516 to518 inclusive. Page43l. 
Fig. 516. The primary, a 
rhombohedron. 
P on P . 
. 85°59 / 
Figs. 517 and 518. 
P on a about . 
. 128° 0' 
P on b or P' on b . 
123 14 
SPHENE. Figs. 519 to 528 inclusive. Page 433. 
Fig. 519. The primary. 
, (according to 
Beudant), an oblique rhombic prism. 
M on jVP. 
. 133°30' 
M or M' on P . 
. 121 50 
Fig. 520. The primary, 
(according to 
G. Rose.) 
M on RP . 
.. 76° 2' 
M or M' on P . 
..93 1 
