Bob Carnein
Joined: 22 Aug 2013
Posts: 353
Location: Florissant, CO
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 Posted: May 05, 2025 12:41 Post subject: Quartz Twins |
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Considering the great recent "Rocks & Minerals" articles by Carl Francis and Pete Richards on quartz twins, I will post a few specimens from my collection.
| Mineral: | Quartz |
| Locality: | | Crystal Peak area, Teller County, Colorado, USA |  |
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| Dimensions: | 9.6x3x2.5 cm |
| Description: |
| Smoky quartz, Left-handed Dauphine twin |
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| Viewed: |
62 Time(s) |
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| Mineral: | Quartz |
| Locality: | | Switzerland | |
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| Dimensions: | 7.2x3.5x2.8 |
| Description: |
| Right--handed Dauphine twin from an unknown Swiss locality. This is a bit odd, in that the crystal exhibits only 2 trapezohedral x faces--one at the "upper right" corner of the front-facing prism face and the other in the "middle" of that prism face, at a suture line. |
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| Viewed: |
62 Time(s) |
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| Mineral: | Quartz |
| Locality: | | Switzerland | |
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| Dimensions: | 7.2x3.5x2.8 |
| Description: |
| Closer view of x faces on a quartz crystal from an unknown Swiss locality |
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| Viewed: |
62 Time(s) |
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| Mineral: | Quartz |
| Locality: | | Gamsberg area, Windhoek District, Khomas Region, Namibia | |
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| Dimensions: | 4.6x2.1x1.3 cm |
| Description: |
| Left-handed Dauphine twin exhibiting both repeating x faces and repeating s faces. Striations on the s faces all point downward toward adjacent x faces (see close-ups below). |
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| Viewed: |
62 Time(s) |
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| Mineral: | Quartz |
| Locality: | | Gamsberg area, Windhoek District, Khomas Region, Namibia | |
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| Dimensions: | 4.6x2.1x1.3 cm |
| Description: |
| Close-up showing s face exhibiting striations pointing downward toward adjacent x face. |
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| Viewed: |
62 Time(s) |
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| Mineral: | Quartz |
| Locality: | | Gamsberg area, Windhoek District, Khomas Region, Namibia | |
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| Dimensions: | 4.6x2.1x1.3 cm |
| Description: |
| Close-up of another s face with striations pointing downward toward adjacent x face. |
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| Viewed: |
62 Time(s) |
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| Mineral: | Quartz |
| Locality: | | Mount Malosa, Zomba District, Malawi | |
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| Dimensions: | 4.3x1.6x1 cm |
| Description: |
| Smoky quartz crystal with unknown inclusions. This crystal exhibits Brazil twinning, as shown by symmetric repitition of x faces on both sides of front prism face. See close-up below. |
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| Viewed: |
62 Time(s) |
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| Mineral: | Quartz |
| Locality: | | Mount Malosa, Zomba District, Malawi | |
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| Dimensions: | 4.3x1.6x1 cm |
| Description: |
| Close-up of previous photo, showing symmetrical repitition of x faces. It appears that the x faces are each actually 2 faces; perhaps a more adept crystallographer can tell me what the "extra" faces are? |
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| Viewed: |
62 Time(s) |
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| Mineral: | Quartz |
| Locality: | | Hunter Canyon, Huachuca Mountains, Hartford District (Huachuca Mountains District), Cochise County, Arizona, USA | |
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| Dimensions: | 3.9x2.3x1.1 cm. |
| Description: |
| According to the person I bought this from, this odd little crystal is from Hunter Canyon, Huachuca Mts., Arizona. Although I suspect it's a contact Dauphine twin, I am not certain and would appreciate comments. Close-up shows very odd distribution of faces around a "notch" at the contact between the two twin halves. |
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| Viewed: |
62 Time(s) |
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| Mineral: | Quartz |
| Locality: | | Hunter Canyon, Huachuca Mountains, Hartford District (Huachuca Mountains District), Cochise County, Arizona, USA | |
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| Dimensions: | 3.9x2.3x1.1 cm. |
| Description: |
| Close-up of previous photo, showing "notch" separating two twin halves and odd distritution of adjoining faces. |
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| Viewed: |
62 Time(s) |
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