Fluorescent “Poker Chip” Calcite

Description

Layered white tabular crystals on a grey stone matrix, with a violet appearance shown in the accompanying UV photograph.

From the Liancheng Manganese Deposit in Fujian Province, this cabinet specimen displays overlapping white Calcite plates with the distinctive tabular “poker chip” form. The broad faces and stepped edges catch the light as the piece is turned.

The second photograph shows the specimen under ultraviolet light, where it appears violet. The precise colour and brightness can vary with the UV wavelength, camera and viewing conditions.

It weighs 870 g and measures 175 × 115 × 45 mm. Please examine the 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, 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 × 115 × 45 mm, with a recorded weight of 870 g. Its scale gives the natural architecture room to be appreciated as a whole, while the finer growth provides detail for closer study.

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.