1. Ruby from Sumeng, Myanmar
The chemical composition of Su Meng ruby was compared with other important producing areas such as Lu 'an in Vietnam, Morogoro in Tanzania, Gu Mo in Myanmar, Kenya, Sri Lanka, Malawi and Thailand, and the following characteristics were found: ① The content of Cr2O3 in Su Meng ruby was the highest; ②FeO content is lower than other marble rubies such as Morogoro in Tanzania and Lu 'an in Vietnam; High content of TiO 2; ④ ④ The content of V2O3 is similar to that of Gumu ruby, but much higher than that of marble rubies in other places. The content range of FeO, TiO2 _ 2 and Cr _ 2O _ 3 in Su Meng ruby is different from that in basalt ruby (such as Thai ruby). The composition characteristics of trace elements are helpful to distinguish Su Meng ruby from its synthetic ruby. Although it may appear to overlap with other marble rubies in data, the composition characteristics of trace elements are of guiding significance for roughly distinguishing the origin of a single sample. Table 4- 19 gives the chemical composition data of Samung ruby in Myanmar. It can be seen that the Cr content is directly proportional to the refractive index value. The sum of trace element concentrations (FeO+TiO _ 2+Cr2O _ 3+V2O3+Ga2O _ 3) is also in good agreement with the refractive index.
Table 4- 19 Chemical Composition Data and Refractive Index of Samung Ruby in Myanmar
Note: Due to manganese dioxide, K2O, magnesium oxide, calcium oxide and silicon dioxide, the total amount of oxides shown here is not 100%. The existence of CuO, NiO, ZrO2 _ 2, nb2o _ 5 or nb2o _ 5 was not detected. @ indicates that there is no obvious shadow boundary on the refractometer.
2. Ruby from Lu 'an, Vietnam
According to the data of electron probe analysis, the content of w(Cr2O3) is 0. 19% ~ 2.08%, the content of W (TiO 2) is 0.0 1% ~ 0.23%, and the content of W (FeO) is 0.01%~ 0. The content of w(FeO) in purple ruby is 0.02%~0.30%, but it is lower than that in Thailand, which shows the chemical composition characteristics of marble ruby.
3. Kenya Ruby
There are differences in chemical composition between Kenyan Mangari ruby and Baringo ruby. Mangari ruby contains low content of W (TiO _ 2) of 0.005% ~ 0.20%, high content of W (V2O3) of 0.0 1% ~ 0.04% and high content of W (Cr2O3) of 0.005% ~ 1%. The content of w(Ga2O3) in Baringo rubies is generally lower than the detection limit, while the content of w(Fe2O3) is higher, ranging from 0.38% to 0.79%, and the content of W (Cr2O3) is 0.05% to 0.29%, and the content of W (V2O3) is generally undetectable.
4. Madagascar ruby
The chemical composition of Andy Ramena ruby in Madagascar is different from that of Vatu Mahndri ruby. The iron content in Andy Ramena corundum is relatively high: generally, the content of w(Fe2O3) is 0.3%~0.9% (individual can reach 1%~ 1.4%). Ultraviolet-visible-near infrared absorption spectrum shows that iron exists in the form of Fe3+ and/or Fe2+.
The content of chromium in Andy Ramena ruby varies greatly, and the content of w(Cr2O3) ranges from 0. 1% in pink to 3% in deep red. The content of w(V2O3) ranges from 0.02% to 0.04%, but as low as 0.005%. The content of titanium in corundum is low to medium, and the content of w(TiO2) is 0.005%~0.03%. The content of gallium is relatively stable, and the content of w(Ga2O3) is 0.005%~0.02%. The contents of titanium, vanadium, iron and gallium in Andy Ramena red and sapphire are almost completely overlapped in the comparison chart. The obvious difference is that the content of chromium in ruby is much higher than that in sapphires of different colors.
Fingerprint characteristics of Watu Mahndri ruby: The chromium content of rubies in this area is within the range of the chromium content of rubies in other areas. The content of w(Fe2O3) is 0. 1%~0.7%, which varies widely, but the overall content is high. The iron content of many Vatu Mahndri rubies reaches the level of typical basalt rubies. The content of V also varies greatly. Some samples are close to the detection limit, while others may reach the level of Gumu or Su Meng ruby (up to 0.07%w(V2O3)).
5. Afghan Ruby
The most important trace element in Zadaleka ruby in Afghanistan is Cr. Table 4-20 gives the semi-quantitative EDXRF chemical element analysis of rubies in this area. Cr content is directly proportional to the depth of red and pink. Titanium, iron, gallium, vanadium, calcium, zirconium, potassium, manganese and zinc are detectable trace elements.
Table 4-20 Semi-quantitative EDXRF Chemical Element Analysis Table of Zadaleka Ruby in Afghanistan
6. Mozambican Ruby
The semi-quantitative EDXRF analysis of Niassa ruby in Mozambique shows that the chromium content [w (Cr2O3): 0.20% ~ 0.67%] and the iron content [w (Fe2O3): 0.40% ~ 0.62%] are moderate, and the titanium content [w (TiO2): (40 ~1762) is moderate. The chemical composition is similar to that of Wenza ruby, which is within the range of chemical element content of many East African rubies.
Through the analysis of 60 samples, the chemical fingerprint characteristics of Nyasa ruby can be summarized as follows: the content of w(Cr2O3) ranges from 0. 10% to 0.85%, and the content of W (Fe2O3) is the same as that of w(Cr2O3), ranging from 0.20% to 0.80%, and the content of most samples is 0.30%. W (TiO _ 2) content is very low, mostly 0.005%~0.030%, and the maximum limit is 0.040%. The content of w(V2O3) in some Nyasa ruby samples ranges from 0.005% to 0.030%, and some w(V2O3) contents are below the detection limit. The content of w(Ga2O3) in Nyasa ruby is very low, mostly less than 0.0 10% or below the detection limit. Table 4-2 1 is the comparative data of chemical composition analysis of Niassa ruby in Mozambique by gemologists in recent years.
By comparing different trace elements in rubies, the trace element characteristics of Nyasa ruby can be obtained more intuitively, and the "fingerprint" characteristics can be found better (Figure 4- 122, Figure 4- 123).
Table 4-2 1 Comparison Table for Chemical Composition Analysis of Niassa Ruby in Mozambique
* indicates that the concentration is extremely high (rarely occurs): * * indicates that the concentration is usually below the detection limit (EDXRF) of the method used.
Fig. 4- Comparison of Cr2O3 and Fe2O3 contents in Mozambique +022 Niassa ruby.
Fig. 4- Comparison of W (TiO _ 2) and W (V _ 2O _ 3) Contents in Mozambique +023 Nyasa Ruby.
7. Ruby of Tajikistan
The chemical fingerprint characteristics of Tajikistan ruby produced in Pamir Plateau are: the content of most elements is quite different. The content of W (TiO _ 2) is 0.0 1% ~ 0. 1%, and the content of V is generally low, and the content of w(V2O3) is mostly between 0.0 15%~0.05%.
The content of w(Cr2O3) in pink varieties is usually 0.20%~0.75%, and the abnormal variety can reach 65438 0.2%. The content of iron varies greatly. In most cases, the concentration of w(Fe2O3) is 0.0 1%~0.03%, and some of them are as high as 0. 1%. A few w(Fe2O3) contents are below the detection limit. Only the content of Ga is stable, and the content of w(Ga2O3) is 0.005%~0.020%.
8. Tanzanian Ruby
The chemical composition analysis of rubies in Wenza, Wengba and Morogoro mining areas in Tanzania shows that the content of w(Cr2O3) is generally 0. 10%~0.60%, and the content of w(Cr2O3) in blue to purple blue sapphires is 0. 10%~0.30%.
The content of iron in rubies in this area is high, and the content of w(Fe2O3) in 95% samples is 0.30%~0.80%. W(Fe2O3) in a few samples can reach 65438 0%. Among them, the top Winza ruby is characterized by relatively low w(Fe2O3)(0.30%~0.40%) and relatively high w(Cr2O3)(0.40%~0.60%). The content of w(Fe2O3) in the blue-purple warm sapphire is 0.60%~0.95%.
The content of Ti in Wenza ruby with the best color is very small, even undetectable. The content of w(TiO2) in other color samples is 0.005%~0.02%. The content of V in rubies from this area is generally low, with a small amount of w(V2O3) below the detection limit (0.005%), most of which are in the range of 0.005%~0.0 15%, and only a few can reach 0.02%. For most samples, the content of Ga is below the detection limit.
The elements in Wenza ruby were analyzed by LA-ICP-MS laser ablation plasma mass spectrometer. It is found that the contents of silicon, chromium and iron are very high, all higher than 500× 10-6(0.05%). Boron, sodium, magnesium, phosphorus, titanium, vanadium, cobalt, nickel, copper, gallium, tin, tantalum, tungsten and lead are also common. The contents of sodium, magnesium, titanium, chromium, vanadium and iron have changed, while the contents of other elements are relatively stable. V and Ti are weakly proportional (Table 4-22).
The w(Cr2O3) content of Umba rubies (mostly purplish red, orange red or brownish red) is mostly 0. 1%~0.3%, which is relatively low. W(Fe2O3) content is 0.5%~ 1.3%, which is obviously high.
Table 4-22 Chemical Element Analysis Table of Tanzanian Winza Ruby (LA-ICP-MS Analysis) (× 106-)
The chemical fingerprints of rubies produced in Morogoro are similar to those of marble rubies from other places, with the contents of w(TiO2) 0.02%~0.05%, w(V2O3) less than 0.02%, w(Cr2O3) 0. 10% ~ 0.49% and W (Fe2O3) less than 0.02.
9. Australian Ruby
Ruby in barrington belongs to metamorphic rock type. Chromium can be detected in both ruby and sapphire. The content of w(Cr2O3) in ruby is 0.5%~ 1.2%, and the highest is 1.4%. W(V2O3 content) is low, less than 0.01%; The maximum content of w(Ti2O) is 0.06%, which is usually lower than the detection limit of EDXRF. W(Fe2O3) content is high, mostly 0.4% ~ 0.6%; W(Ga2O3) content is usually lower than 0.0 1%.