quality ranges meaning in English

质量范围

On the basis of the study on the mineral composition and rock types of jadeite , the authors determine that the specific density and refractivity of jadeite ranges from 2 . 93 to 3 . 60 and from 1 . 593 to 1 . 750 respectively , the specific density and refractivity of jadeite with high quality ranges from 3 . 178 to 3 . 240 and from 1 . 644 to 1 . 657 respectively , and offers the objective basis for jadeites quality appraisal , through setting up several charts of the relation between jadeite ' s specific density refractivity and its mineral composition
从翡翠的岩石学、矿物学角度出发，讨论了翡翠的岩石类型，依据组成翡翠的主要矿物的比重和折射率值，建立了翡翠矿物组成成分及含量与其比重、折射率关系图解，确定了各种翡翠的比重、折射率变化范围分别为： 2 . 93 ~ 3 . 60和1 . 593 ~ 1 . 750 ；优质翡翠的比重、折射率分别为： 3 . 178 ~ 3 . 240和1 . 644 ~ 1 . 657 ，为翡翠的质量评估提供了客观依据。