Dallasite

Dallasite is a breccia made of subequant to rectangular or distinctly elongate, curvilinear shards that represent the spalled rims of pillow basalt (see: Hyaloclastite).

This material is commonly partly altered to chlorite, epidote, quartz and carbonate, for which the local term 'dallasite' has been coined.

[1] The stone dallasite is named after Dallas Road, Victoria, British Columbia.

It is considered the unofficial stone of British Columbia's capital city.

[2] Dallasite is found in Triassic volcanic rocks of Vancouver Island and is considered the third most important gem material in British Columbia.