Manganese-bearing “Poker Chip” Calcite

Description

A broad, open cluster of overlapping white and pale grey crystal plates with varied angles and layered edges.

This Liancheng specimen has a striking open arrangement of tabular Calcite crystals. Large plates rise above smaller intergrown layers, while the pale grey and white faces catch the light at different angles. Dark flecks and exposed matrix give contrast near the base.

It is identified as manganese-bearing and fluorescent. No UV photograph is included with this listing, so the exact colour and strength of its response have not been specified.

The specimen weighs 638 g and measures 175 × 90 × 42 mm. Please examine all six photographs for its crystal edges, surfaces and matrix; the exact piece shown will be supplied.

The tabular growth gives this Calcite a layered appearance. Broad faces establish the shape, while the repeated edges draw attention to smaller stages within the crystal groups. “Poker chip” is a descriptive habit name rather than a separate mineral species. It is this arrangement of plates, rather than colour alone, that makes the specimen distinctive.

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 175 × 90 × 42 mm, with a recorded weight of 638 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.