Mechanical,Optical And Acoustic Properties And Significance Of Nephrite

Nephrite has a long history,permeated with huaxia brilliant civilization.In the sites of ancient culture in our country,the jade unearthed is given priority to nephrite and serpentine jade.In this paper,explorations and analysises are made about the optical characteristics,the mechanical properties of nephrite,and the subjective evaluation about Whether the sound is pleasant or not as well as the objective measuring data.Firstly,the experiments of infrared spectrum and X-ray powder diffraction are taken,and it is shown that nephrite’s main components are tremolite and less impurities of chlorite.Nephrite researched varieties in different ultraviolet-visible absorption spectra,and its color is associated with transition metal Fe²⁺and Fe³⁺.However,whether the presence of the chlorite affects the amount of Fe or whether it is associated with the color of the nephrite need to be further studied.The relative density of nephrite sample is about 2.86～3.09,with a Vickers hardness of 568.76～800.73 N/mm².Green nephrite compressive strength in the range of 192.24～377.03 MPa by uniaxial compression test,the tensile strength between21.64～62.88 MPa by splitting test,it can be seen as the compressive strength is strong and the tensile strength is also prominent.In the meantime,The ratio of rock’s compressive tensile strength can be used to indicate the situation of rock’s toughness,as the bigger the value,the greater the brittleness.On the contrary,the value of ratio is smaller,the toughness of rock becomes stronger.The ratios of compressive tensile strength measured on green nephrite are 9.06,9.83,and 3.06 less than granite,basalt,rhyolite,limestone,quartzite,marble or other volcanic rocks or metamorphic rocks.So nephrite’s toughness is better than common rocks.In addition,if the tremolite particles is smaller and the combination between particles are closer,the ratio of rock’s compressive tensile strength will be smaller and the toughness will be better.According to the sounds from different jades,it is divided into three levels:the sound of the nephrite and agate for level 1,the sound of the aventurine quartz and Lantian jade for the secondary,and the sound of the serpentine jade for level 3.The sounds of nephrite and agate are the best.The acoustic testing results show that the frequency values of nephrite are higher than serpentine jade and glass,less than the jadeite jade.According to the calculation of the length of sound,a sorting on different jades is made as jadeite jade,nephrite,serpentine jade from long to short.Piece of jade chip has nice acoustic characteristics,and the spectrum shows that the fundamental tone is purity.In the spectrum of nephrite,the fundamental tone and overtone constitute a non-integer times on the vibration frequency,and the relationship between the overtone are arranged to open.Some of harmonic with high strength can still affect people’s sense of sound as to produce a general feeling of register.Meanwhile,The sound intensity of nephrite is slightly higher than jadeite jade and serpentine jade,it may be the reason why it sounds louder and clearer.