BY W. F. PETTERD, C.M.Z.S. 171 



on galena; and has been reported as occurring at the old 

 Scamander Silver Mine. 



312. Steinmannite (Sulphide of Lead and Antimony). 



What is apj^arently this mineral occurs in small but 

 perfectly developed octahedral crystals of a tin-white 

 colour and bright lustre. They range from 1 to 5 milli- 

 metres in diameter. In habit they are found singly or in 

 bunches of three or four crystals implanted in cavities of 

 the green-stained dolomitic gangue, and more rarely as 

 small reniform masses, the surfaces of which are often 

 studded with well-formed crystals. In the druses they are 

 usually accompanied by bright little yellow crystals of 

 sphalerite, and equally well-developed crystals of quartz 

 Before the blowpipe on coal they give unmistakable 

 reactions for lead and antimony. 



So far these crystals have only been detected in the 

 workings of the Heazlewood Silver-lead Mine. 



313. Sternbergite (Sulphide of Silver and Iron). 



A rare silver ore that belongs to the orthorhombic 

 system. The crystals are thick, tabular, but more often 

 they occur as thin plates. The lustre is metallic, but com- 

 monly much tarnished. 



The only known occurrence in this State was at what 

 was known as the Godkin Extended Mine, where it was 

 found in close association with huascolite and galena. 



314. Stilbite (Hydrated Silicate of Aluminium and 



Calcium). 



This mineral has occurred, with other zeolites, as a 

 somewhat finely divergent mass of a yellow-brown colour 

 in the amygdaloidal basalt in the vicinity of Bell Mount, 

 Middlesex. Its common mode of occurrence is in diverg- 

 ing and radiating groups, the prisms of which are not 

 rarely several inches in length. In crystallisation it is 

 monoclinic. The crystals are often in the form of cruci- 

 form penetration twins. 



315. Stibiconite (Hydrous Oxide of Antimony). 



A pale pulverulent mineral which occurs in amorphous 

 earthy masses. It has occurred in small quantity at th^^ 

 ^ritish-Zeehan Mine, Zeehan. 



