NOTES ON SOME MINERALS. 85 



yellow to sherry red, transparent, opaque. Fig. 14 is of a crystal 

 from this locality, it is however exceptional with reference to 

 development of prism. 



Spinel. 

 At Oban (N.E.), in the Ann River and above its junction with 

 the Mitchell River, also in the Mitchell River, in rounded pieces 

 with rough surfaces, appears as if little waterworn, but without 

 trace of crystalline form. Colour, dark wine-red, transparent ; 

 observed up to 15 J carats in one specimen, average for six others 

 6.6 carats each. The spinels from the Ann River are generally 

 free from flaws and imperfections. Sp. G. 3.69, hardness over 8 

 scratches topaz readily. Found with gold, tin ore, titanic iron, 

 topaz, zircon, and sapphire. Fragments of spinel are found with 

 gold and other minerals at Bingera, Rocky River, and Nundle 

 goldfields, but are generally small or opaque. A piece from 

 Uralla weighed considerably over 1,000 grains, had a Sp. G. of 

 3.81, was rose-red, but dull and opaque, and very much waterworn. 



Gahnite. 

 About half-a-mile west from Great Northern Railway, at a 

 point about two and a half miles north from Bolivia Railway 

 Station. Occurs as a lode or vein ten to twelve inches wide, in 

 granite. Massive, crystalline. Some very small cavities exist in 

 the mass, in which the mineral has crystallized out in minute 

 octahedral forms. Colour of massive mineral, dull bluish-grey, 

 opaque ; crystals greyish, with violet tinge, and transparent. 

 Contains an admixture of feldspar. Sp. G. 3.56. 



Pleonaste. 

 Pleonaste occurs more or less plentifully with zircons and 

 sapphires, at Apple Tree Gully, near Tnverell. At Swamp Oak 

 Creek, in the Inverell District, and about Paradise Creek (County 

 Gough). At the zircon locality, on road from Glen Innes to 

 Inverell, and among the pebbles in the beds of the Clairvaux and 

 Furracabad Creeks, near Glen Innes. Also on south side of, and 

 one quarter of a mile from the crossing of the Severn River, on 

 road from Emmaville to Inverell. Generally occurs in broken 

 fragments, irregularly shaped, rough, or waterworn and smooth ; 

 pieces 60 to 70 grains, common. Occasionally in tolerably perfect 

 crystals. Black, opaque, exterior dull, but newly broken surfaces 

 very lustrous. Fracture conchoidal, tough. Sp. G. 3.91, hardness 

 over 8, scratches topaz. 



Yesuvianite (Idocrase). 

 Near crossing, and on eastern side of Ironbarks Creek, on New 

 Road from Barraba to Bundarra (N.E.), in minute yellowish 

 crystals, lining cavities in massive garnet. Crystals, transparent 



