|Rocks and minerals|
- I put lots of igneous rocks also under the category of volcanology, but since igneous rocks is also a subcategory of volcanology, maybe they shouldn't be there. Any thoughts? Gwimpey 23:43, 11 Jun 2004 (UTC)
- There should be a subcategories of Igneous rocks into Felsic, Mafic, Intermediate, or even Potassic, Ultrapotassic rocks, alkaline, etc. Or is this too pedantic? I can see this could become a fight between placing certain rocks into either categories, or more than one, eg, kimberlite or lamproite could be both ultramafic and ultrapotassic, and probably should be both. Thoughts?Rolinator 03:35, 28 January 2006 (UTC)
Another thought (see discussion on list of rocks); We should aim to have only IUGS-sanctioned rock types on lists such as this. For instance, rhomb porphyry, unakite, napoleonite, Vaasa granite, are igneous rocks but are essentially plaace-names. This goes against the IUGS classification scheme.
- Lapidiary stones (eg; Unakite) should be reclassified to elsewhere
- Metasomatic rocks (Unakite; Uralite) should not be placed here
- Textural varieties of other rocks should not be placed here, for example, "orbicular granite" is still just a granite; rhomb porphyry is a porphyritic volcnic rocks beter known by its official name.
- Individual intrusions, volcanic formations, igneous complexes, etc should not be categorised as an Igneous Rock. Yes, they are igneous, but every individual intrusion cannot be placed in this category.
However, differentiating amongst the various broad classifications (granitoids, for instance) is fine; there is a mineralogical and genetic difference between a granite and a tonalite. Rolinator 02:21, 19 February 2006 (UTC)
Seeing that the category igneous rocks is very mixed, large and not well suited to do fast search I have crated the following subcategories:
- Igneous rocks by composition
- Calc-alkaline rocks
- Felsic rocks
- Intermediate rocks
- Mafic rocks
- Ultramfic rocks
- Ultrapotassic rocks
- Igneous rocks by texture
- Aphanitic rocks
- Vitreous rocks
- Phaneritic rocks
- Granitic rocks
- Ophitic rocks
- Porphyritic rocks