1) Beautiful stone 2) Cubic mineral 3) Cut mineral 4) Decorative stone 5) Gemstone 6) Gemstone mineral 7) Jewel mineral 8) Jewel 9) Mineral 10) Mineral gemstone 11) Mineral jewel 12) Polished jewel 13) Polished mineral 14) Precious gem 15) Precious jewel 16) Prized mineral 17) Precious gemstone 18) Precious stone 
Langbeinite is a potassium magnesium sulfate mineral with formula: K2Mg2(SO4)3. Langbeinite crystallizes in the isometric - tetartoidal system as transparent colorless or white with pale tints of yellow to green and violet crystalline masses. It has a vitreous luster. The Mohs hardness is 3.5 to 4 and the specific gravity is 2.83. The crystals are...
Potassium magnesium sulfate
[n] - a mineral consisting of potassium magnesium double sulphate
noun a mineral consisting of potassium magnesium double sulphate; used as a fertilizer