The Yunnan Ruili and in Beijing's jewelry market presented one kind to be called one after another: “two colors are valuable” (or mandarin duck treasure) new gem variety. This gem its outward appearance red and the green two kind of colors simultaneously appears for the characteristic on grain of abstention surface. Its end product does not have the facet, ponders over assumes the solid colored, has the circular, the ellipse, the water-drop shape and the heart shape common and so on. “is valuable to such two colors”, has wide divided opinions, in the market to red part, thinks is the ruby, but to green part, then has different explanations, some people said likely the jadeite, some people said likely the diopside. After the concerned expert's detailed determination and the research, verify the red part is a ruby truly, but green part for black curtain stone. “two colors are valuable” are area Ruili common people's popular name, has bright red and the green two kind of colors according to a gem in gives a name. “two colors are valuable” are the common people hold the gem prominent outward appearance characteristic, the visualized name, is accepted very easily by the people, therefore by widespread use. may see from the research results, “two colors are valuable” should belong to one kind including the balas (ruby) the porphyritic crystal green black curtain rhododendron obtusum, chooses a name the principle according to the common precious jade petroleum section study, in the gem may choose a name as “the corundum black curtain stone” or “the red valuable black curtain stone”.