Strathglass, Aird and Loch Ness, Highland, Scotland, UKi

Regional Level Types
Strathglass	- not defined -
Aird and Loch Ness	Ward
Highland	Council Area
Scotland	Country
UK	Country

Locality: Loch na Meine Mine, Strathglass, Aird and Loch Ness, Highland, Scotland, UK

Habit: The anglesite crystals, two of which were measured, are elongated in the direction of the c-axis and show the forms a (100), λ (210), h (340), o (011), and y (122). The faces (100), (210), and (340) are deeply fluted vertically from repetition.

Colour: colourless to greyish

Description: A single specimen only was found at the Loch na Mèine working. It shows minute, up to 2 mm., colourless to greyish bladed crystals occupying a cavity in galena and baryte, with a little quartz, cerussite, and a coating of pyromorphite on which are minute crystals of wulfenite.

Localities:

Habit: coarsely lamellar; elongated in the direction of the b-axis and showing the forms (100), (110), (102), (011), the two latter largely developed, (021), (111), (122), also narrow faces of (166) between (011) and (122).

Colour: pink; white; colourless

Description: small transparent crystals not exceeding 8mm.

Locality: Struy Bridge, Struy, Strathglass, Aird and Loch Ness, Highland, Scotland, UK

Locality: Allt Tighe Cumhaig, Struy, Strathglass, Aird and Loch Ness, Highland, Scotland, UK

Locality: Allt Tighe Cumhaig, Struy, Strathglass, Aird and Loch Ness, Highland, Scotland, UK

Colour: colourless

Description: At the level on Allt Tigh Cumhaig burn on the surface of the black crystallized blende there are sprinkled numerous small, up to 5 mm., beautiful water-clear symmetrical stout hexagonal prisms (1010),(0001) of calcite which often support crystals of harmotome. From the level on the first burn north of Allt Tigh Cumhaig a specimen was obtained showing a cavity in platy baryte, lined with crystals of calcite (1 1/2 cm.) and baryte, the calcite crystals showing the simple but unusual combination of the hexagonal prism (1120) with the scalenohedron (2131) and basal plane (0001).

Locality: Loch na Meine Mine, Strathglass, Aird and Loch Ness, Highland, Scotland, UK

Habit: Small patches and small, up to 5 mm., colourless crystals of varied habit in pyromorphite-lined cavities. These crystals are prismatic in the direction of the c-axis and either simple or twinned on m (110); they show the forms b (010), c (001), m (110), x (012), k (011), i (021), p (111); others are pyramidal in habit and twinned on m (110). Axial ratios and letters for this and the other minerals here described as in Dana's System of mineralogy, 6th edition, 1892.

Locality: Allt Tighe Cumhaig, Struy, Strathglass, Aird and Loch Ness, Highland, Scotland, UK

Locality: Allt Tighe Cumhaig, Struy, Strathglass, Aird and Loch Ness, Highland, Scotland, UK

Habit: coarse

Colour: pink

Localities:

Localities:

Habit: often doubly terminated, the appearance of the terminations varying much, depending on the relative development of (100) or (110); likewise, the re-entrant angle of (001) may be very prominent or insignificantly developed. The (100) faces are striated parallel to their intersections with (010); their terminal edges are, however, often slightly inclined away from the centre of the cross, and when this is the case the faces are seen to be fluted in two directions, the upper portion parallel to the intersection with (010), the lower parallel with (001), a step-like medial line forming the boundary between the two and suggesting oscillation between (100) and (001) in the lower half. On (010) the medial line is generally very distinct and slightly raised; the characteristic herringbone striae, though often distinct, are by no means always visible. Optical examination of this face shows how very complex the crystals are, the sectors overlapping in a most irregular manner with erratic lines of junction. Associated with the cruciform twins there are smaller 1 1/2 mm. water-clear crystals, combinations of (001), (100), and (010). On these crystals, the striae on (100) are considerably out of parallel with the intersection with (010).

Colour: colourless

Description: The crystals are small, up to 5 mm., but are very beautiful, exhibiting various modifications of the characteristic complex cruciform twins. The harmotome crystals are emplanted on crystals of blende, on baryte or calcite, and sometimes directly on the pink felspathic rock itself. Sprinkled on them and also included in them are minute crystals of pyrite and marcasite. Harmotome, a mineral formed during the very last phases of hydrothermal action, occurs here as elsewhere in veins containing baryte which have an igneous rock for one or both walls, in this case, one wall being a pegmatite. The mineral exhibits a remarkable resistance to weathering; hence the freshness of the crystals, despite having lain so long on the dumps.

Locality: Allt Tighe Cumhaig, Struy, Strathglass, Aird and Loch Ness, Highland, Scotland, UK

Locality: Allt Tighe Cumhaig, Struy, Strathglass, Aird and Loch Ness, Highland, Scotland, UK

Localities:

Locality: Allt Tighe Cumhaig, Struy, Strathglass, Aird and Loch Ness, Highland, Scotland, UK

Locality: Loch na Meine Mine, Strathglass, Aird and Loch Ness, Highland, Scotland, UK

Habit: crusts of minute grass-green stout hexagonal prisms; also siskin-green slender tapering prisms investing pyramidal crystals of quartz, and more rarely minute golden-yellow transparent prisms associated with cerussite and wulfenite.

Colour: grass-green; siskin-green; golden-yellow

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Localities:

Colour: black

Localities:

Habit: Acute pyramidal. The crystals are sharp and well-defined and consist of the acute pyramid (111) either alone, or usually in combination with (221), the prism (110), and base (001). The faces (111) are slightly curved except at the apex and merge by repetition into those of (221) and (110), giving the whole crystal a curved outline, some, in fact, being almost barrel-shaped. The basal plane (001) is never smooth, the surface being either square-pitted or studded with innumerable extremely minute (111) pyramids. The faces of (110) are horizontally striated from repetition with the adjoining pyramids, while on most of the crystals the surfaces of (110), (221), and (111) are covered with raised and overlapping outlines of acute pyramids giving them a scaly appearance. In some crystals, two parallel pyramids (111) terminate a single prism (110). The measurements obtained from each of the faces are poor, but good enough to identify the forms with certainty.

Colour: Orange-red, rarely golden-yellow with blotches of red.

Description: Very small, not exceeding 2 mm. The crystals either project from, or lie flat on, thin crusts of minutely crystallized green pyromorphite, which invests baryte, small bipyramidal crystals of quartz, or hacked quartz from which baryte has been leached. On other specimens single crystals of wulfenite project from cavities in massive baryte lined with ochre. Sometimes as many as 25 minute crystals are present on a square inch of the pyromorphite-covered surface. The wulfenite appears to have been the last mineral formed. In a few cases, wulfenite crystals are penetrated by and have grown round prisms of pyromorphite.

Locality: Struy Bridge, Struy, Strathglass, Aird and Loch Ness, Highland, Scotland, UK