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58 Made of Lancaster. 



a rectangular cross, the entering; angles being truncated- 

 Fig. 4th represents a group of crystals arranged in the 

 form of a true crosS; but having a small^ solid crystal in 

 the centre. Fig. 5tli represents a section of a very hard 

 and compact crystal, which has a black rhomb in the 

 centre, from which lines diverge to the solid angles, divid- 



ing the crystal into four parts, the lines being in the 

 diagonal of a square. Fig. 6th, i Ic represents a very 

 curiously complicated group of crystals ; the whole 

 being two inches long from the extremity i to Zr. A very 

 remarkable difference is observable betw^een the figures 

 of the base and summit. Fig. 7th represents two crys- 

 tals intersecting each other at angles of 60^ and 120^. 

 Fig. 8th, Oth, 10th, and 11th are views of extremely 

 hard crystals which are found in micaceous argillite ; their 

 forms are peculiar. Fig. 10th shows an emarginate crys- 

 tal. Fig. 12th3 a twin group. Fig. 13th, a crystal having 

 a little quadrangle in the centre, surrounded by a crust of 

 red colored Made and the whole exterior of the crystal is 

 enclosed in a pearly crust which may be easily cleaved 

 from the enclosed crystal. Fig. 14th represents a soft 

 decomposing crystal of a greenish grey color. Fig. 15th 

 represents a very delicate line of the Made arranged in 

 the shape of a rhomb. Fig. 16th, a very hard crystal, 

 having all the characters of the common Andalusite, ex- 

 cepting the minute rhomb in the centre* Fig. 17th, a 

 singular group of separate crystals. Figs. 18th, 19th, 20th, 

 and 21st, other varieties of form assumed by this curious 

 mineral. 



From measurement of more than a hundred specimens 

 1 find the form of the white or reddish substance of the 

 Made to be a right square, or rectangular prism, some- 

 times a little rhombic. Tlie form of the Andalusite is, 

 according to Phillips, 91^ 20' which nearly coincides 



