Where is Garnetiferous Granite found?
Granite with Almandine Garnet
Got a photo? Identify rocks instantly with the Rockby app
Open the appGarnetiferous Granite occurs in specific geological environments. Knowing where to look, and in what kind of rock, is the difference between going home empty-handed and finding a great specimen.
Where to find Garnetiferous Granite
Appalachian Mountains, USA
Various localities, particularly in New England (e.g., Maine, New Hampshire) and the Piedmont region, where granitic intrusions are associated with Paleozoic orogenic events and contain assimilated metasedimentary material.
Fennoscandian Shield, Europe
Parts of Norway, Sweden, and Finland contain Proterozoic and Archean granitic complexes, some of which are garnetiferous due to high-grade metamorphic processes and subsequent melting.
Himalayan Orogen, Asia
Granites formed during the collision of the Indian and Eurasian plates often contain garnets, reflecting the melting of high-grade metamorphic rocks at depth.
Western Australia
Certain Archean and Proterozoic granite-greenstone terrains and mobile belts can host garnetiferous granites.
Brazil
Parts of the Brazilian Shield contain granitic intrusions with garnet, related to various Precambrian orogenic cycles.
Collecting tips
- Look for Orogenic Belts. Garnetiferous granites are often found in regions that have undergone significant mountain-building events (orogenies), as these processes create the necessary conditions for their formation.
- Examine Outcrops for Red Crystals. Visually inspect granite outcrops for distinct, dark red to reddish-brown, often well-formed, isometric crystals embedded within the lighter-colored matrix. These are likely almandine garnets.
- Check Associated Metamorphic Rocks. The presence of nearby high-grade metasedimentary rocks (like garnet schist or gneiss) can indicate a higher likelihood of finding garnetiferous granites, as these can be source rocks for the garnet-bearing melt.
- Use a Hand Lens. A hand lens (10x magnification) will help in identifying the characteristic crystal forms and luster of the individual minerals, especially the garnets, and distinguishing them from other dark minerals like biotite.
Quick Check
- Color:
- Light-colored matrix (white, gray, pink) with distinct dark red to reddish-brown crystals.
- Luster:
- Overall granular, with vitreous to resinous garnets.
- Streak:
- White (for the felsic minerals); garnets typically have no streak or a very faint reddish-brown streak on unglazed porcelain, but are too hard to streak easily.
Explore Garnetiferous Granite
Identify rocks anywhere
Free on iOS, Android, and Web. Photo identification, full database, and your personal collection.