24 
ORES OF MANGANESE. 
.555. Calamine, impure earthy 
variety. 
Castleton, Derhyshire. 
556 & 557. Cala^iine, common 
impure variety. 
Fi 'om the Lead and Calamine 
Works, in the Mountain Lime¬ 
stone, Mendip Hills, Somerset¬ 
shire. 
558. Calamine, common earthy 
variety. 
Whorle Llill, near Weston-super- 
Mare, Somersetshire. 
558a. Calamine, newly dis¬ 
covered, 1862. 
From Sheshodonnel, near Castle- 
town, Co. Clare. 
Shelf \ Ill. 
559. Blende, black, fine crys¬ 
tallized specimen, Avith quartz en¬ 
crusting. 
Laxey Mines, Lsle o f Man. 
Presented by Mr. BeckTV'ith. 
560. Blende, massive, crystal¬ 
line. 
From Laxey Mine. 
Presented by Captain Rowe."^ 
560a. Blende and Galena cry¬ 
stallized. 
Aid stone ?vIoor. 
Ores of Manganese. 
The ores of manganese occur in irregular repositories in Devon and 
Eastern CoriiAvall, in North Wales, &c., but are raised in only small 
quantity from the British islands. As they are largely employed, in 
part for the extraction of manganese and in part for jdelding oxygen, 
the demand is chiefly supj)lied from the Continent. 
Wall Case 13. 
Fyrolusite ] Prismatic Man¬ 
ganese Ore; ( anhydrous hinox- 
ide), contains about 63 per cent, 
of metal. 
PIausmannite ; Black Alanga- 
nese ; {anhydrous proto-jjeroxide 
of Manganese), contains about 72 
per cent, of metal. 
Manganite ; Grey Manganese 
Ore ; {hydrated peroxide), con¬ 
tains about 62 per cent, of metal, 
and 10 per cent, of Avater. 
Psilomelane ; compact Manga¬ 
nese Ore ; its chemical composition 
varies, but it contains, Avith oxide 
of manganese, Avater and baryta. 
Most of the foiloAving specimens 
Vv^ere presented by Sir Henry De 
la Beche. 
Shelf I. 
561. Psilomelane, botryoidal 
and massive. 
Tresweeta, St. Stephens, Corn¬ 
wall. 
562 & 563. Psiloaielane, mas¬ 
sive, compact. 
Brent Tor, rear Tavistock, Devon¬ 
shire. 
564. Psiloaielane. 
Vicinity of Tavistock, Devonshire. 
565. Pyrolusite, crystallized, 
and ma;ssive. 
Upton Pyne, near Exeter, Devon. 
566. Pyrolusite, occurs min¬ 
gled Avith Haematite in a lode 
traAmrsiug Mountain Limestone. 
At Owargoch, Neivton Down, 
Glamorganshire. 
Slielf II. 
567. Psiloaielane, mammil- 
lated, and stalactitic. 
Brent Tor, Tavistock, Devonshire. 
568. Pyrolusite upon Psilo¬ 
aielane, lamellar, fibrous, frac¬ 
tured and re-cemented by nature. 
Bestormel, Lostwithiel, Cornwall. 
569. Psiloaielane, stalactitic, 
and massive. 
Glandore, County Cork, Lreland. 
Presented by Captain Tomkins. 
* A A^ery fine specimen of Zinc-blkxde, of highly crystalline character, associated 
with quartz, and exhibiting its masswe occurrence in the Laxey lode, is placed in the 
pedestal case. 
