54 MINERALS OF TASMANIA. 
yock. They are tabular felspars, not unlike the New Guinea 
felspars in obsidian, described in the No. 1 of the Rhyolites.” 
182. PHACOLITE (Hydrated Silicate of Alumina and 
Calcium). 
A variety of the zeolitic mineral Chabasite, which occurs in 
modified crystals of lenticular form. It is abundant in basalt 
rocks. Near Waratah; Hellyer River; Lefroy; Sheffield; 
Springfield. 
183. PENTLANDITE (Iron-nichel Pyrites). 
As small irregular patches of metallic lustre, with Magnetite, 
Zaratite, and Serpentine. 
Heazlewood. (Montgomery.) 
184. PYCNITE (a variety of Topaz of cylindrical form). 
Occurs scattered throughout Quartz-porphyry. Mt. Bischoff. 
185. PLATINUM. 
This has been reported to occur at St. Paul’s River; Pieman 
River gold-field; in auriferous drift as minute flakes, but 
occasionally in the form of small cubes, Blue Tier, near Beacons- 
field. 
186. PLUMBOGUMMITE (Hydrated Phosphate of Lead and 
Alumina). 
Occurs in stalactitic and irregular globular forms of a pale- 
brown colour and resinous lustre. 
British Zeehan mine, Zeehan. 
187. PERICLASITE (Owide of Magnesia). 
River Don (James Smith); as a vein in Serpentine, sometimes 
enclosing lumps of that mineral ; it is white and compact. North 
of Trial Harbour, near the Pulpit Rock. 
188. PYRITES (Sulphide of Iron). 
This well known mineral is generally diffused throughout the 
metalliferous districts of the island ; it occurs—primary or secondary 
—in rocks of all geological ages. The auriferous form occurs at 
Beaconsfield, Lefroy, and Mathinna. Well-formed crystals are 
plentiful at Beaconsfield ; Zeehan; Dial Range, and Bischoff. 
Massive, granular, and sub-crystalline formations of large size 
have been discovered at Mt. Lyell, Mt. Reed, and the Dial Range ; 
on the Forth River between Mt. Claude and Middlesex Plains a 
very large band occurs between Mica Schist and metamorphic 
Slate—it is said to be auriferous ; occasionally obtained decomposed 
to brown hematite at Dundas and Beaconsfield ; an extensive 
cupriferous pyrites formation reported to be about 140 feet in 
