Precursor glasses and glass-ceramics comprising a crystalline phase having a jeffbenite crystalline structure

A glass-ceramic article, comprising:

• a first major surface and a second major surface facing away from the first major surface, edges forming a perimeter of the first and second major surfaces and extending between the first and second major surfaces;
• wherein a thickness of the article is defined as distance between the first and second major surfaces, a width of the article is defined as a distance along the first major surface orthogonal to the thickness and between the edges, and a length of the article is defined as a distance along the first major surface orthogonal to both the width and thickness and between the edges;
• wherein the width is greater than or equal to the thickness;
• wherein the length is greater than or equal to the width;
• and
• a body between the first major surface, the second major surface, and the edges, wherein the body comprises in mole percent (mol. %) on an oxide basis:
• greater than or equal to 35 mol. % to less than or equal to 65 mol. % SiO2;
• greater than or equal to 5 mol. % to less than or equal to 20 mol. % Al2O3;
• greater than or equal to 7 mol. % to less than or equal to 65 mol. % MgO;
• greater than or equal to 0 mol. % to less than or equal to 7 mol. % ZrO2;
• greater than or equal to 0 mol. % to less than or equal to 15 mol. % Na2O;
• greater than or equal to 0 mol. % to less than or equal to 15 mol. % K2O;
• greater than or equal to 0 mol. % to less than or equal to 9 mol. % FeO;
• greater than or equal to 0 mol. % to less than or equal to 10 mol. % MnO2;
• and
• greater than or equal to 0 mol. % to less than or equal to 15 mol. % ZnO;
• wherein the body comprises a phase assemblage comprising one or more crystalline phases and a glass phase, wherein the one or more crystalline phases comprise a crystalline phase comprising a jeffbenite crystalline structure;
• wherein grains of the crystalline phase having the jeffbenite crystalline structure are homogeneously distributed throughout the body;
• wherein the grains of the crystalline phase having the jeffbenite crystalline structure overlap and interlock with one another within the body to a degree such that fracture toughness thereof is 0.75 MPa·m1/2 or greater.