RocksdayNepheline Syenite vs Syenite
To tell Nepheline Syenite from Syenite: Syenite is quartz-poor too, but it lacks nepheline.
A coarse rock of alkali feldspar and nepheline, with no quartz. It is the home of many rare minerals.
Photo: Jstuby, CC BY-SA 3.0
Looks like granite but has little or no quartz; mostly alkali feldspar.
Photo: James St. John, CC BY 2.0
Key differences
- Syenite is quartz-poor too, but it lacks nepheline.
Side by side
| Property | Nepheline Syenite | Syenite |
|---|---|---|
| Type | Igneous rock | Igneous rock |
| Mohs hardness | 5.5–6 | 6 |
| Luster | Granular | Granular |
| Colors | Gray, White, Pink, Green | Pink, Gray, White |
| Crystal system / structure | Coarse-grained, no quartz | Coarse-grained (phaneritic) |
| Specific gravity | 2.5–2.7 | 2.6–2.8 |
| Found in | Bancroft, Ontario; Khibiny, Kola Peninsula, Russia | Magnet Cove, Arkansas; Ontario, Canada |
Properties that are the same for both are grayed out.
How to identify nepheline syenite
- Pale gray, pink or green, coarse grained.
- No glassy quartz — nepheline is greasier and softer.
- A knife may scratch the nepheline.
Structure: Coarse-grained, no quartz
Full Nepheline Syenite guide →How to identify syenite
- Coarse pink or gray feldspar crystals.
- Little or no glassy quartz.
- Some dark hornblende or biotite.
Structure: Coarse-grained (phaneritic)
Full Syenite guide →More comparisons
Frequently asked questions
What is the difference between nepheline syenite and syenite?
Nepheline Syenite is an igneous rock with a Mohs hardness of about 5.5–6 and a granular luster, usually gray, white, pink or green. Syenite is an igneous rock with a Mohs hardness of about 6 and a granular luster, usually pink, gray or white.
How can you tell nepheline syenite from syenite?
Syenite is quartz-poor too, but it lacks nepheline.
Could you tell them apart from a blurry close-up?
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