103 



and apophyllite; the sapoiiite is the first formed mineral hut 

 is only found in some places as small spots on the walls 

 of the cavity; the gyrolite forms a stratum, whose thickness 

 varies from ^/2 to 2 cm, and upon that stratum the apophyllite 

 is found as rather large (1—2 cm) cubelike crystals, which 

 quite fill up all the spaces between the gyrolite so that freely 

 developed crystals of that mineral are not to be found. The 

 gyrolite, itself, is as usual crystallized in foliated masses ar- 

 ranged rather irregularly; the surfaces of the cleavage folia are 

 rather strongly curved in all directions. I have not succeeded 

 in producing percussion or etching figures upon them ; the 

 specific gravity of the purest material is 2'446. 



2. Nu sak, on the southside of the peninsula of Nug- 

 suak, the district of Ritenbenk. The specimens are col- 

 lected by Rink and the rock seems to be a breccia with numerous 

 cavities in which are found: (ll a radiated columnar mineral pro- 

 bably scolecite in the form of globular masses of a diameter up 

 to 2 cm, (2) gyrolite forming a stratum of 1 to 3 cm thickness 

 and (3) small grains of quartz of quite irregular form implanted 

 upon the gyrolite and probably younger than this mineral; the 

 gyrolite is crystallized in radiating foliated aggregations and it 

 is possible to cleave out quite regular and even folia of a 

 diameter up to 1 cm ; crystalline faces are not found. Percus- 

 sion figures cannot be made and the etching figures, produced 

 by hydrofluoric acid, are quite marked but of a rounded, almost 

 circular, form. The specific gravity is 2'412. 



3. Niakornarsuk, near the foregoing place. From here 

 we have a small specimen collected by Steenstrüp with a single 

 cavity (6 cm) the walls of which are covered with a thin 

 {I — 2 mm) stratum of thomsonite arranged in globular masses 

 as is commonly the case; upon that mineral saponite or gyrolite 

 is found, where they are found together the gyrolite is the 

 younger of the two. Upon all the three other minerals are 

 implanted flat crystals of apophyllite (see the figure 101 in 



