Fluorescent “Poker Chip” Calcite on Matrix

Description

A tall cabinet specimen of pale white to soft grey Calcite, with broad tabular crystals layered across the matrix. The overlapping “poker chip” forms have a pearly lustre and stepped edges, creating a sculptural display with detail from several angles.

The bevelled glass display base is included.

Supplied as manganese-bearing fluorescent Calcite. These photographs show the specimen in ordinary light; its ultraviolet fluorescence is not pictured in this gallery.

Locality supplied: Liancheng Manganese Deposit, Liancheng County, Longyan, Fujian Province, China.

The crossing arrangement described above is an important part of the specimen’s silhouette. It lets the direction of individual crystals be followed through the group, with open spaces making their outlines more apparent. Intersecting crystals alone do not establish a specific twin law; here the description concerns the visible arrangement rather than a laboratory-confirmed crystallographic relationship.

Calcite is calcium carbonate, a mineral with an unusually wide range of crystal forms. It occurs in sedimentary rocks, mineral veins and many other geological settings. Although the composition remains broadly the same, differences in growth conditions can produce dramatically different outlines, from broad faces to slender or densely grouped crystals. This variety is part of its interest for a mineral collection.

Calcite has well-developed cleavage: it can split along particular planes in its crystal structure. Its natural growth faces and cleavage surfaces therefore deserve careful distinction. Transparent, translucent and more opaque examples all occur. The shape, arrangement and surface character of this piece are more informative than colour alone, especially when comparing specimens from different localities.

The recorded origin is Liancheng Manganese Deposit, Liancheng County, Longyan, Fujian Province, China. Within a collection of Calcite specimens, this locality gives the piece a geographical identity alongside its particular crystal habit and natural setting.

The specimen measures 200 × 83 × 74 mm, with a recorded weight of 1004 g. The proportions give a useful guide to its place in a display, with the individual crystal arrangement and mineral association remaining the principal points of interest.

Calcite is relatively soft and has pronounced cleavage, so support the stable part of the specimen when moving it. Avoid pressure on thin plates or projecting points. A secure display helps preserve the delicate edges and the arrangement of growth described for this piece.