Is Runed Stalactite legal in Standard, Modern, and Commander?

Runed Stalactite is legal in: Modern, Legacy, Vintage, Commander, Pauper.

What type of card is Runed Stalactite?

Runed Stalactite is an Artifact — Equipment. Its oracle text reads: "Equipped creature gets +1/+1 and is every creature type. Equip {2} *When a changeling adopts a form no other changeling has taken, a rune appears in the caverns of Velis Vel to mark the event.*"