Orthorhombic crystals are usually short, whith a characteristic diamond-shape or rectangular shape in cross section. These crystals form 4-sided prisms and pyramids. Orthorhombic crystals have three axes that are at right angles to each other, and all of the three axes are of unequal length. Monoclinic crystals are stubby, with tilted, matching faces at opposite ends that make them look like distorted rectangles. They form into prisms and open forms that are made up of two parallel faces.
Monoclinic crystals have three axes that are unequal in length.
Two of the axes will be at right angles to each other, and the third will be at an inclined angle to the other two axes. Triclinic crystals are generally flattened, with sharp edges and thin cross sections. They lack right angles on faces or edges, and they form into open forms with two parallel faces. Triclinic crystals have three axes, that are all different in length and none of them form right angles. Gemstones Gemstones are minerals or rocks that can be cut and polished, and have enough beauty and durability to be used in jewelry.