Siderite - gemmy crystals
Morro Velha Mine, Nova Lima, Iron Quadrangle
6.1 x 4.3 x 3.1 CM (cabinet)
Early summer 2021
Cluster of transparent to translucent Siderite crystals with stepped and modified Rhomb forms dominating. With backlighting this glows a deep honey-yellow color and is quite lustrous. In good shape overall there are some rough spots but none are major. The Siderite from this locale is some of the best in the world. The largest flattened rhomb on this piece is 3.1 CM across, and has sharply stepped faces.
A fine Yaogangxian multi-specie specimen hosting a prominent Siderite crystal perched on sparkling purple Fluorites. In excellent condition, we do not see much good Siderite from this famed locale that is better known for world class Fluorites and Sulfides. There are small crystals of several other species present as well as is typical from this locality, a comprehensive label can get quite long! Ex Shields and Frances Flynn collection, an excellent example of the specie from this iconic locale.
An exceptional Swiss alpine specimen of perfect curved rhombs in an esthetic stack. From a less well known locality at the Gauli Glacier in the Bernese alps. This zone is not well known for minerals but as the large glacier has been retreating some things have come to light. Recently (August of 2018) a heatwave uncovered a WW2 vintage US aircraft that is the second such wreck uncovered on Gauli. This Siderite is elegantly formed with a few small quartz and Rutile crystals as minor accessories. In exceptional condition and very eyecatching, this is a super Siderite from anyplace but especially choice and rare in such perfection from the Alps.
A monster! The main crystal is as large as these have ever been found, and one of the best. The big crystal measured on the edge is 7.5 CM and on the diagonal is 9.8 CM across. Very impressive, this piece is one of the top three of the giant St Hillaire Siderites, and outstanding for the specie world wide. Sharp and fairly lustrous as well, the honey brown color has yellow highlights and is translucent. The matrix is the sort of elongated Albite crystals that look a lot like Natrolite. Ex Hitchings collection, obtained in 1967 the early part of the "golden years" at St Hillaire. In fine condition there is a contact on the backside but no damage. Even the smaller crystals in the cluster here would be choice specimens alone but they add a nice esthetic touch to the whole piece.
A superb example of this very special find with a sharp, sparkling rhomb of Siderite (3.4 CM) perched perfectly on a mix of Quartz, Chalcopyrite, Galena etc. In perfect condition with nice architecture and contrast, this displays very well from every angle. Ex John Marshall collection, these were never common and have been very hard to find now for many years.