PEGMATITE

Major Rock Type: Igneous
Formation: Jerai Formation
Age: Cambrian (540 - 485 million years ago)
Origin: Singkir Darat, Yan, Kedah

* This rock has been extracted from the Singkir Darat Quarry in Yan, Kedah, known as pegmatite, is a fascinating geological specimen with a unique composition and structure. It was dated that the age of this rock was from Cambrian Period, approximately 540 to 485 million years ago.

* Pegmatite is an igneous rock which has a mineral composition similar to granite. The predominant mineral constituents are quartz and feldspar, creating a beautiful interlocking of colours and textures.

* The quartz crystals, often translucent and colossal while the feldspar crystals exhibit a creamy white hue. These minerals are accompanied by the presence of mica minerals like muscovite and biotite, contributing their shiny, flaky appearance to the rock.

* The only difference is that pegmatite has larger sized minerals and these minerals can be easily observed in the pegmatite boulders.

* Pegmatite minerals grow to unusually large sizes due to the exceptionally slow cooling process during their formation, allowing crystals to reach several meters in length.