We present 4x4 mm square cut stones to better emphasize the color variation in different techniques of production. We grow, or used in the past, hydrothermal emeralds using four different techniques and they produce 4 different results: (a) "Regular" (our original, original method of product that resembles color of Zambian emeralds) is produced in a stainless still autoclave, the resulting stones have bluish tint; this product is the most widely used in the market and production is still the largest; (b) Newer method uses platinum-lined crucibles and the result is different type of emerald with different color (much less blue) and some different properties; (c) In 2001 we acquired "Biron" production plant in Australia and re-started production; these emeralds are grown in gold-lined crucibles and the result yields yet a different product; (d) Our latest technique that took 9 years to develop, is Colombian color emeralds. As a bonus, we added to this set a bi-color beryl, half green, half red.