京白玉为一种质地细腻、光泽油润的白色石英岩，由于最早在北京西部郊区开采，故取名京白玉，后在全国多处发现，分布极广。矿物学属石英岩类。其特点是石英颗粒细小，玉质纯白均一。
Beijing white jade is a fine and shiny white quartzite. Because it was first mined in the western suburbs of Beijing, it was named Beijing white jade. It was later found in many parts of the country and widely distributed. Mineralogy is a quartzite class. It is characterized by fine quartz particles, pure white jade.京白玉玉质较纯，通体质白，无杂色。以纯白、闪蓝、闪绿色为可用之材，其中以脂白为上。京白玉内部粒状结构，晶粒越小越细腻，结构特征不明显。京白玉硬度为摩氏6度，性脆，易打出断口，断口呈玻璃碴状。
Beijing white jade jade quality is more pure, through the white constitution, no miscellaneous color. With pure white, flash blue, flash green as the available materials, among which to fat white as the top. The internal granular structure of Beijing white jade, the smaller the grain, the more delicate, the structure characteristic is not obvious. Beijing white jade hardness is 6 degrees Mo, brittle, easy to break, the break is glass ballast.此藏品名为“大清乾隆京白玉砚台”，重：3532.5g 长：约31.5cm 宽：约25cm。京白玉质地细腻、光泽油润均不作任何人为沁色，规整的器形端庄雅致，此件藏品纹理极为优美，极其精致，呈现出自然奔放的艺术效果。就仿佛是一幅油画，美得动人心魄，是众多收藏家钟爱的藏品，“京白玉砚台”的收藏价值极高，是绝世宝物。温润的玉材，规整的器形端庄雅致，充分体现了乾隆时期的审美趣味，是当时的杰作。
The collection is called "Gan Longjing White Jade Ink-stone of the Qing Dynasty", heavy: 3532.5g long: about 31.5cm wide: about 25cm. Beijing white jade with fine texture, shiny oil are not refreshing for anyone, and the neat shape is dignified and elegant. This collection is very beautiful in texture, extremely delicate, presenting a natural, bold and unrestrained artistic effect. It is as if it is an oil painting, which is a favorite collection of many collectors, and the collection of "Beijing white jade inkstone" is of very high value, which is a unique treasure. Warm jade material, the formal shape is dignified and elegant, fully reflects the aesthetic taste of the dry long period, is a masterpiece at that time.整体雕工精致，线条流畅，底落款“乾隆年制”，琢工精细，造型端庄。乾隆时期的玉器以它精湛的工艺博得世人的喝彩，在雕琢技法上堪称一流。“乾隆玉器”之所以在各大拍场上屡创高价，有其独特历史环境的因素。乾隆时期政治局面的稳定，国力昌盛，财富的空前积累为奢侈享受提供了充足条件，精美艺术品受到皇室贵族的垂爱。
The overall carving is exquisite, smooth lines, the bottom of the signature "dry dragon year system", exquisite carving, dignified modeling. Jade in Ganlong period won the world with its exquisite craftsmanship, which can be called first-class in carving techniques. The reason why "Ganlong Jade" has repeatedly hit high prices in the major auction venues has its unique historical environment. The stable political situation in the Ganlong period, the prosperous national strength and the unprecedented accumulation of wealth provided sufficient conditions for luxury enjoyment, and the exquisite works of art were loved by the royal family.如果要探究起中国砚台的起源，可能要追溯到原始社会人类打造工具的研磨器了，作为与笔、墨、纸并称“文房四宝”，中国历代的文化人对砚台的珍爱，可以说是到了无以复加的地步了。刻砚、赏砚、藏砚，作为一种时尚的风气，砚台随着社会历史的演变，浓缩了中国各个朝代文化、经济乃至审美意识的各种信息。对现代人来说，古砚台完成了由实用品到艺术品的转化，因而也造就了它独特的收藏理财的价值。
If we want to explore the origin of Chinese inkstone, it may be traced back to the grinding tool of human building tools in the primitive society. As being known as the "four treasures" with pen, ink and paper, the cherish of Chinese cultural people for inkstone can be said to be to the point of incomparable. As a fashionable atmosphere, the inkstone, with the evolution of social history, concentrates the various information of the culture, economy and even the aesthetic consciousness of various Chinese dynasties. For modern people, the ancient inkstone has completed the transformation from real supplies to art, and thus also created its unique collection of financial management value.