GRANULITE
Granulite is a term that modern metamorphic geologists don’t appear to
like or use for a rock type any more. Traditionally, granulites were
considered to be very high-grade metamorphic rocks having a medium- to
coarsely-crystalline texture with ~same-sized crystals. Granulites lack
obvious foliation at a fine scale, but some do show a weak gneissic foliation
at a coarse scale (see “Toasted Almond Granite” below).
Several “granites” sold in the decorative stone trade are actually
granulites.
Granulite (“Kashmir White Granite”) - this attractive garnetiferous
granulite from India was metamorphosed during the early Mesoproterozoic (~1.4
billion years ago). The rock has feldspar (white), quartz (grayish),
garnet (deep red), and biotite mica (black). This material is quarried at
several localities near Melur Taluk (for example, Keelavalavu, Malampatti,
Navinipatti, and Tirukalambur), Madurai District, southern Tamil Nadu State in
the far-southern Eastern Ghats Orogenic Belt of far-southern India.
Granulite (“Toasted Almond Granite” or “Ghibli Granite”)
- this is another Proterozoic-aged granulite from India’s Eastern Ghats
Orogenic Belt. It comes from near the city of Ghibli, Tamil Nadu State,
southern India. Note the slightly elongated crystals that give the rock a
subtle foliation extending from the top to the bottom of the photo.