Virtual Museum ID: 19-LDM11
The color in amethyst from most localities is unevenly distributed in the individual crystals. In amethyst geodes, it is often most intense in the growth zones under the rhombohedral faces (at the tips). Occasionally the color is deeper under either the r or z rhombohedral faces, giving the crystal a pinwheel appearance when viewed from the top. In prismatic crystals, the color may appear in phantom-like thin layers, while in scepters and skeleton quartz the color is often concentrated along the edges, and accompanied by smoky zones. Despite the intense color, the content of iron occupying Si positions in amethyst is rather low, in the 10-100 ppm range (Dennen and Puckett, 1972).
When heated to more than about 300-400°C, amethyst loses its violet color and often turns yellow, orange or brown, and then resembles the quartz variety citrine, but depending on the locality and the temperature during the heat treatment it may also turn colorless or - rarely - green (Rose and Lietz, 1954; Neumann and Schmetzer, 1984).
The information listed below relates to the current holding location or collection that the sample is from, and whether the item is viewable at that location or is part of a private collection. Coordinates are given as guides, and we remind you that collecting specimens from these locations is not allowed. Caution is advised visiting such sites and Below BC assumes no responsibility for any injuries or trespassing charges that may occur as a result of the viewer entering these sites.
Original Collection:Lakes District Museum (LDM)
Virtual Museum ID:19-LDM11
Date Added to VM:2019-08-23
Sample Origin:Terrace, B.C.
Datum:09 (NAD 83)
Primary Mineral Formula:SiO2
Advanced Geological Information
The following section provides geological data relating to the specimen or the site it was collected from, when available. Information has been obtained from various sources including private and government datasets but may not be up to date. Any geological time periods or ages listed often relate to the primary geology of the area, and may not be the actual date of an event such as mineral formation.