Ultramafic

(of igneous rocks) Where dark coloured or mafic minerals make up more than 90% of the rock
Found on https://www.encyclo.co.uk/local/20501

Ultramafic

Rock that is rich in magnesium and iron content.
Found on http://www.physicalgeography.net/physgeoglos/u.html

Ultramafic

Igneous rocks made mostly of the mafic minerals hypersthene, augite, and/or olivine.
Found on http://www.encyclo.co.uk/local/21455

Ultramafic

Igneous rocks made mostly of the mafic minerals hypersthene, augite, and/or olivine.
Found on http://volcano.oregonstate.edu/glossary/1

Ultramafic

Igneous rock consisting essentially of ferromagnesian minerals with trace quartz and feldspar.
Found on http://www.australian-shares.com/glossary-of-terms.php.html
No exact match found