K2 Stone from Pakistan
K2 stone is a fascinating rock named after the world's second-highest mountain, K2. It's part of the Karakoram Range, close to the border of Pakistan and China.
It was initially reported to be white granite with distinctive orb-like markings of blue azurite.
In some K2 stone, the azurite is so distinctive that it resembles blue dye. In some stone, subtle traces of malachite can also be seen.
K2 stone grades 6 on the Mohs scale of hardness but is prone to visible signs of wear if not handled carefully.
It's found at the base of a steep slope in a rarely visited part of the Karakoram Mountain Range.
When K2 stone first appeared on the market some years ago, geologists were not convinced the blue marks were natural. This thread on Mindat, the world's largest database of rocks and minerals, makes an interesting read.
When scientific testing was carried out, this was the result:
- Blue spots: The striking blue spots in K2 stone are likely azurite. These blue grains have high birefringence, which means they bend light in two different ways, making their optical properties more difficult to analyse under a microscope.
- The rock itself is composed of:
- Microcline: A type of feldspar, often pale or pinkish
- Quartz: Clear or white crystals, common in many rocks
- Biotite and muscovite: Two types of mica, which are flaky, shiny minerals
- Plagioclase feldspar: A type of feldspar.
The rock is granite gneiss or granodiorite, both types of igneous rock changed by heat and pressure (metamorphism).
It likely started as one of these rocks before being altered.
K2 stone is a mix of regular granite-like rock with striking blue azurite spots that formed during its geological history.
I've seen some material being sold as K2 Jasper, which is geologically incorrect.
It's generally believed the blue spots in some material from China have been enhanced.
The K2 stone in our collection is rough and unpolished. The intriguing blue marks are mostly visible on one side. The depth of colour, amount of azurite staining and size of each mark varies from piece to piece. No two stones are the same.
In dimmed light, minute sparkling crystals can be seen.
This K2 stone is sold by weight, so please make your selection from the listings below. The stone you may not be one of the stones shown in the photo. However, if you choose a listing with a photo of a single stone, that is the piece you'll receive.
