![]() I was confused for a moment, not knowing what it was. When I found it, it was turned about 45 degrees clockwise, so that it looked like a squared off crystal. ![]() In addition, because so many or the crystals from Boylston are red or orange due to iron staining, they quite unique in the province.Ī tabular red quartz crystal from Boylston.īelow is a very distorted quartz crystal from Boylston. In many cases this is related to the developemnt of Fadens, described above. Orange Faden quartz growth from Boylston.Ĭurved Faden quartz growth from Boylston.īoylston has produced some very nice tabular crystals of quartz. There might be lateral or torsional movement that causes the Faden to be curved as in the figure below. Of course the fissure need not open evenly. If the fissure opens smoothly, then the final quartz crystals are all parallel. Because the original grain was crystalline, all of the additional material grown over it is oriented in the same direction. Key to the formation of Faden quartz is that there is a relationship between the crystallographic orientation of the original grain and the final quartz crystals. Fadens are generally found in what are known as Alpine type deposits.Īnimation of the formation of a quartz Faden. This process is shown in the simple animation below. Finally at some latter point in time, quartz crystals grew around the milky colored Faden. As a fissure in the rock opened up over time, the grain continued to break and reheal and reconnect, forming the Faden. The theory of development is that the Faden formed first, beginning as a simple grain of quartz. The term Faden is German for string and is the adopted term used to describe a a white line running through a crystal or group of crystals. Though the twinning would extend down the prism, there is no change in luster to make it visible. In the lower picture the crystal edges are outlined in black and the twinned zones are outlined in white. On the other hand the z and z faces are lustrous.Ī crystal showing lustrous and dull patches on the terminal faces, in a pattern that indicates twinning. All of the r faces are dull and in the twin, the r faces are also dull. ![]() To make the following description simpler, let us assume that the dull face that makes up the majority of the large lefthand face, is the r form. In this case, the faces show lustrous and dull patches due either to etching or a thin coated (to be determined). Click on picture to enlarge.īelow is another manifestation of a Dauphiné or Brazil twin. The s faces are visible at positions 1, 4 and 5 (tiny sliver). This is the most likely scenario.Ī probable Dauphiné or Brazil twin, based of the positioning of the s faces. The other is that the crystal is partially twinned according to either the Dauphiné or Brazil laws. Six prism faces and another six termination faces are usually all that are present (forms m are both present, but the complimentary form is considered rare. ![]() Quartz crystals are typically very simple in their habit. With hope, additonal localities will turn up in the future to produce more specimens of this excellent mineral. There have been some interesting finds of quartz in Nova Scotia, however, as is typical, most of the finds appear to have been small. If time is spent looking more closely at the crystals, however, we can learn a lot more about crystals and crystalline matter. Well formed colorless crystals with smooth faces and sharp edges are very common and appealing in their simplicity. Quartz is one of the most abundant minerals and is a mineral that just about everyone knows.
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