276 



SCIEXCE-GOSSIP. 



SOME SCARCE MINERALS. 



A TlXERALOGISTS are familiar -with the form 

 ■*■" of sulphide of antimony named Stibnite, 

 •which has long and slender crystals, in appearance 

 not unlike highly polished steel. To enable such 

 of our readers as may not have had opportunity of 

 seeing this beautiful mineral to obtain a better idea 

 of its formation we have had drawn a group of the 

 crystals through the courtesy of Mr. Samuel 

 Henson, of 97, Regent Street, London. He has for 

 some time past been receiving small consignments 

 of this mineral from a nephew in Japan, who now 

 sends the doleful intelligence that 

 the mine from which they were 

 obtained no longer produces these 

 fine specimens. They will there- 

 fore be probably unobtainable. 

 The longer crystal we figure is 

 thirteen inches in length. There 

 is a magnificent group of Stibnite 

 from this source in the national 

 collection at the British Museum, 

 South Kensington, which includes 

 about 120 crystals, some thirteen 

 inches in length, and from half- 

 an-inch to two and a half inches 

 in width, the whole group weigh- 

 ing no less than i5olbs. This 

 is doubtless one of the most re- 

 markable instances of metallic 

 crystallisation ever met with. 



On a recent visit to Mr. Henson's 

 studio, he drew our attention to 

 an instance of an immense crystal 

 of Thorite doubly terminated. 

 This crystal is two and a half 

 inches long by seven-eights of an 

 inch wide, whereas the usual 

 length is less than half-an-inch. 

 This specimen is from Sweden, 

 and has also been added, through 

 Mr. Henson, to the British Mu- 

 seum. A pretty association of 

 minerals in one piece is repre- 

 sented by the crystals of Rubellite with Lepidolite 

 from California. The base is the delicate sparkling 

 grey Lepidolite, the pink crystals of the Rubellite 

 being beautifully grouped in contrast. 



Another interesting specimen was of the intensely 

 blue Boleite from Boleo, in California, whence this 

 mineral takes its name. This is perhaps one of 

 the largest known crystals of Boleite, being no less 

 than three-quarters of an inch square. Among the 

 examples of the precious metals in a natural state 

 which have passed through Mr. Henson's hands 

 were some remarkably fine native crystals of gold 

 from Ballarat, in Australia, consisting of rhombic - 



Group of Cetstals of Sti3x:te 

 (13 inches long.) 



dodecahedron, octahedron, and cubo-octahedron, 

 ranging in size from one-eighth to one quarter of an 

 inch. A lovely and very valuable specimen of 

 Proustite or ruby silver, some nine or ten inches long, 

 is exceptionally beautiful on account of the rich 

 deep ruby -red crystals. Some specimens of auri- 

 ferous quartz from the celebrated Coolgardie reef 

 indicated no less than seventy-five per cent, of gold. 

 Tasmania has latterly been sending over to 

 England some beautiful specimens of rare 

 minerals. One we saw was a gorgeous piece 

 of Crocoisite, or native chromate 

 of lead, in association with Cerus- 

 site. The brilliant red crystals of 

 the Crocoisite contrasting richly 

 with the silky white Cerussite. 

 Another especially beautiful group 

 of crystals of Crocoisite measured 

 seven inches by five inches 

 across the upper surface of the 

 specimen. 



Another association of minerals 

 forming groups of beauty, are the 

 golden-brown hair-like crystals of 

 Rutile penetrating through the 

 mass of rock-crystals. Rutile is 

 a well-known species of mineral 

 from Brazil, consisting of oxide 

 of Titanium. It does not always 

 occur in this hair-like form, being 

 generally found in masses or 

 heavy crystals. Nature appears 

 with this mineral to have been 

 playing fantastic tricks with the 

 rock-crystal. How these beautiful 

 "hairs" of mineral came to be 

 mixed with the crystal, in the 

 utmost disorder, seems incon- 

 ceivable. It may be that in the 

 first instance when these fairy-like 

 crystals were formed, they were 

 supported by some other medium, 

 which in course of ages decom- 

 posed, to be in turn replaced by the quanz « ith 

 which they are now surrounded. 



To those interested in dendrites Mr. Henson can 

 show a splendid collection, made in India, of some 

 200 specimens of most carefully-selected cut Mocha 

 stones. The moss-like patterns of these crystals 

 are strangely like vegetation in shape. 



It is surprising that more people do not take a 

 closer interest in mineralogy, considering the great 

 beauty and many surprises there are among the 

 specimens of different species to be obtained. 



We shall always welcome in these pages notes 

 cr re— arks upcr. nev.- :r ;:=r;e — i-erals —J T C 



