Database of luminescent Minerals

Lepastrum

Chemical Formula:See BARYTE

Familly: Sulfates

Status:

Crystal System: Orthorhombic

Mineral for Display: No

Luminescence:

Phosphorescence (in the common meaning of the term) seen by naked eye:

Comments:

Old name for Baryte in septaria from England (see label)

Very different from the Nutfield mineral is the barytes occasionally found in the septaria of the London clay, especially in the Isle of Sheppey. Here it occurs in slender opaque white crystals, arranged in radiating forms or in stellate groups, and rather effectively disposed on the yellow calcite which has crystallised in the contraction-cracks of the nodules, and was formerly called the  waxen vein. This occurrence of barytes was recognised by such early observers as Dr. Grew and Sir John Hill, who described the mineral under the name of lepastrum, and appear to have regarded it as gypsum. Some of the specimens here shown (Nos. 1405, 1406) are said to have come from Whitstable Bay ; and according to Sowerby the barytes was also found under similar conditions at Southend, at Sydenham, and at Highgate.

(Text from  HANDBOOK TO A COLLECTION OF THE MINERALS OF THE BRITISH ISLANDS, . MOSTLY SELECTED FROM THE LUDLAM COLLECTION, IN THE MUSEUM OF PRACTICAL GEOLOGY, JERMYN STREET, LONDON, S.W. , BY F. W. RUDLER, I.S.O., F.G.S. LATE CURATOR OF THE MUSEUM. 1905. )

Main Activator(s) and spectrum:

Best Locality for luminescence(*):

• Warden Point, Isle of Sheppey, Swale, Kent, United Kingdom;

(*)Data are not exhaustive and are limited to the most important localities for fluorescence

Bibliographical Reference for luminescence:

Mineralogical Reference on internet:

  http://www.mindat.org/show.php?name=Lepastrum

  http://webmineral.com/data/Lepastrum.shtml

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