28 
THE HALL 
Alabastek. 
Sides of Vestibule. Screen C. Columns , &c., Nos. 79, 88, 
92, 137 and 143. 
The term alabaster was formerly applied to a stalagmitie 
variety of carbonate of lime much used by the ancients for 
ornamental purposes, especially for the manufacture of small 
vases for holding precious ointments ; whence such vessels 
received the name of “ alabastra.” This Oriental alabaster , of 
which the Algerian “ onyx-marble ” is a modern example ( see 
also the slabs, Nos. 21, 24, 25), must be distinguished from 
the mineral which is at present called alabaster ; that name 
being now applied to the fine massive or granular-crystalline 
varieties of gypsum (p. 109). This mineral, which occurs abun- 
dantly in the form of nodules, bands, and veins, in the New 
Red or Keuper marls of our Midland counties, is a hydrous 
sulphate of lime, containing, when pure, sulphuric acid 46 * 51, 
lime 32*56, water 20‘93. Owing to the presence of oxide of 
iron and other impurities, the mineral is rarely uniform in tint, 
but is generally clouded and streaked with red, as seen in the 
specimens exhibited. These are from Fauld, in Staffordshire ; 
and Chellaston Hill, near Ashbourne, in Derbyshire. Alabaster 
likewise occurs near Newark, in Nottinghamshire ; near 
Watchet, in Somersetshire; and elsewhere in Triassic marls; 
whilst it is found in Purbeck strata near Battle, in Sussex, and 
at Swanage in the Isle of Purbeck. 
There is much demand for alabaster by the potters in 
Staffordshire, who form their moulds of plaster of Paris from it, 
whence it has been called potter's stone. In working the 
sfcone the fine blocks are selected, and sold to the turners of 
alabaster ornaments. No. 79 is an illustration of the process of 
working this material for ornamental purposes. It is now 
largely used for internal ecclesiastical decoration. 
Several varieties of alabaster occurring in the province of 
Pisa in Italy are extensively worked into ornamental objects, 
and as the stone is extremely soft, the cost of working is but 
small, and alabaster ornaments are therefore imported into this 
country at a very low price. The purest white alabaster is 
worked by underground excavations in the Val di Marmolaio 
near Castellina, 25 miles from Volterra, in Tuscany. 
Serpentine. 
Cornish Serpentines. — Screen A. Slabs, Columns, Tazze, &c., 
Nos. 51, 60, 128, 130,131, 164, 166, 167,175, 177, 178, 
179, 191, and 201. Cubes in Case III. 
The Serpentine, — so called from the supposed resemblance of 
the rock to the skin of a serpent, — which is found in quantity 
at the Lizard, is undoubtedly the most beautiful of the 
