The Crystal And Synthetics Under Cathode Luminescence Characteristic's Research

The present paper selects the amethyst, the citrine and the crystal (altogether 211 grains) as the object of study, under the BY-1 model cathode luminescence instrument to observe the sample's illumination color, intensity and internal characteristic. Contrastive analyze each kind of colored crystal and the synthetic's illumination characteristic, obtains the crystal's cathode luminescence rule. Test condition: Voltage 7-8kv,electric current 1500μA,microscope enlargement factor is ten.Crystal's cathode luminescence is very weak, minority for weak blue purple. Its synthetics' illumination is the medium - strong red light, occasionally has the blue color; The citrine cathode luminescence is the weak - medium blue purple, partly is the orange red, the synthesis citrine is the weak - medium red light; The amethyst cathode luminescence both has the blue purple and the red light, the synthesis amethyst only shines red, amethyst illumination is higher than its synthetics; As the citrine's and the amethyst's color from shallow to deep, its cathode luminescence's intensity increases gradually, under the cathode luminescence observes crystal's some internal structure characteristic: The crevasse, the gas-fluid inclusion, the colored ribbon, the crystal seed board and so on.Together the quartz color origin with the cathode luminescence characteristic to discuss crystal cathode luminescence mechanism: The crystal is the pure SiO₂ crystal, very little includes the fault of construction and the foreign ion, its illumination is very weak. the synthesis crystal in the growth process, As the crystal's structure changed, has some flaws to become the luminescent center, or in the doping agent includes foreign ion also produces the medium - strong red light.The amethyst and its synthetic's color have relation with the FeO₄^4- color centre this can cause the cathode luminescence to present red. But in the amethyst includes micro Al to make the cathode luminescence assume the blue purple The citrine includes Al³⁺+O^- to present the blue purple, includes the Fe element to present the orange-red light, the citrine may simultaneously present these two kind of colors, but its synthesizes only to be able to present one kind of color. The reasons to cause the cathode luminescence characteristic difference between the amethyst, the citrine and their synthetics include: Crystal and its synthetic's color origin difference; their internal structure characteristic's difference; the synthesis quartz has some flaws in the growth process; the radiation's time and intensity will also affect their cathode luminescence characteristic.The influence cathode luminescence result's factor has three aspects: Sample aspect: sample's size, shape, thickness and color will affect the experimental result; Instrument's adjustment aspect, electron gun's voltage and electric current adjustment; the internal structure characteristic's observation has certain difficulty.