WikiTrade

Mohs scale

The Mohs scale of mineral hardness is a qualitative ordinal scale, from 1 to 10, characterizing scratch resistance of minerals through the ability of harder material to scratch softer material.

On WikiTrade, every Wikipedia article is a card: the more the article is read, the rarer the card. Open free packs, complete your album, trade, bid and challenge others to general-knowledge duels.

Text from Wikipedia (CC BY-SA 4.0). WikiTrade is an independent site, not affiliated with Wikipedia or the Wikimedia Foundation.