Ebonstone - Merven Materials Part 1

Ebonstone, ask. askasia [askaˈsiaː] (Askallan Mystery) is a rare volcanic mineral found exclusively in the Elveros Mountains on the Aure'a island in Mervè. 

Ebonstone is a hard, opaque material. It is black to purple or blue in appearance, with gentle glimmer of lighter tones. It has highly distinctive crystalline markings known as egeia (from ask. egeios, vein), which divide the amorphous material with translucent gold. Egeia are phosphorescent and scintillate gold in the sunlight and pale silver in the moonlight. With artificial light such as flame, they glow gold but without visible shimmer. Ebonstone is believed to be of arcane nature, as egeia tends emit stronger light if exposed to arx.