Gugiaite
A variety of Minerals
What is Gugiaite?
Gugiaite is a melilite mineral, named for the Chinese village of Gugia where it was first discovered. Its chemical formula is Ca2BeSi2O7. It occurs mostly in skarns with melanite adjacent to an alkali syenite and has no economic value. Its crystals are small tetragonal tablets with vitreous luster and perfect cleavage. It is colorless and transparent with a density of three. The mineral belongs to space group P-421m and is strongly piezoelectric. Shortly after the discovery of gugiaite, it was noted that a new name was unnecessary as it could have been considered an end member of meliphanite, (Ca,Na)2Be(Si,Al)2(O,F)2 differing mainly in containing much less Na and F (Fleischer 1963). Recent data have confirmed that gugiaite differs from meliphanite optically and structurally (Grice and Hawthorne 2002). Gugiaite is a melilite and is distinctly different from other beryllium minerals such as meliphanite and leucophanite (Grice and Hawthorne 2002). Gugiaite is named for its locality near the village of Gugia, China (Peng et al. 1962). Incongruent information exists regarding Gugia; consequently the actual location of this village within China is unclear (de Fourestier 2005). Gujia is most often referenced as being in either Jiangsu Province or Liaoning Province (Yang et al. 2001; Mandarino 2005).
Market Value Factors
Pricing varies for every rock and mineral, so use these universal factors to gauge Gugiaite before comparing listings or appraisals.
Size & Weight
Larger, intact specimens usually command higher prices.
Rarity & Demand
Scarce material or popular varieties sell at a premium.
Condition & Finish
Chips, repairs, and heavy wear lower value; clean prep helps.
Treatment & Provenance
Untreated specimens with documented locality are prized.
Gugiaite Localities Map
See where Gugiaite is found with a localities map, collecting zones, and geology context. Generate a sample map preview below.
Key Characteristics
Characteristics of Gugiaite
The crystal form of gugiaite occurs as thin tetragonal tablets mostly 2-3 mm across and 0.3-0.5 mm thick, shown in Figure 2 below (Fleischer 1963). The cleavages are {010} perfect, {001} distinct, and {110} poor (Peng et al. 1962). It is transparent, optically uniaxial (+), and strongly piezoelectric (Peng et al. 1962). See Table for additional physical properties.
Composition of Gugiaite
Gugiaite has an ideal chemical formula of Ca2BeSi2O7 and is a member of the melilite and sorosilicate (Si2O7) groups (Peng et al. 1962). It is chemically similar to jeffreyite (Ca,Na)2[(Be,Al)Si2(O,OH)7], meliphanite (Ca,Na)2[Be(Si,Al)2O6(O,OH,F)], and leucophanite (Ca,Na)2[Be(Si,Al)2O6(O,F)] in that they all contain essential calcium, beryllium, and silicon (Hawthorne and Huminicki 2002). Two chemical analyses gave similar results and one is as follows: SiO2 44.90, Al2O3 2.17, Fe2O3 0.11, MnO 0.07, MgO 0.38, CaO 40.09, BeO 9.49, Na2O 0.72, K2O 0.20, H2O− 0.36, H2O+ 0.90, F 0.25, Cl 0.18, P2O5 0.08, TiO2 trace, -O=(F,Cl)2 0.15, sum 99.94, 99.79% (Fleischer 1963). Common impurities are Ti, Zr, Hf, Al, Fe, Mn, Mg, Na, K, F, Cl, and P (Fleischer 1963).
Quick Facts
Physical Properties
- Color
- Colourless, yellow
- Hardness (Mohs)
- 5
- Density
- 3.03 g/cm³
- Streak
- White
Chemical Properties
- Chemical Formula
- Ca2Be(Si2O7)
- Elements
- Be, Ca, O, Si
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Gugiaite FAQs
How do I identify Gugiaite?
Gugiaite can be identified by its hardness of 5 on the Mohs scale, Colourless color. Look for these key characteristics when examining specimens.
What color is Gugiaite?
Gugiaite typically appears in Colourless, yellow. Color can vary depending on impurities and formation conditions.
How hard is Gugiaite?
Gugiaite has a hardness of 5 on the Mohs scale. This gives it moderate hardness.
What is the characteristics of gugiaite of Gugiaite?
The crystal form of gugiaite occurs as thin tetragonal tablets mostly 2-3 mm across and 0.3-0.5 mm thick, shown in Figure 2 below (Fleischer 1963). The cleavages are {010} perfect, {001} distinct, and {110} poor (Peng et al. 1962). It is transparent, optically uniaxial (+), and strongly piezoelectric (Peng et al. 1962). See Table for additional physical properties.
What is the composition of gugiaite of Gugiaite?
Gugiaite has an ideal chemical formula of Ca2BeSi2O7 and is a member of the melilite and sorosilicate (Si2O7) groups (Peng et al. 1962). It is chemically similar to jeffreyite (Ca,Na)2[(Be,Al)Si2(O,OH)7], meliphanite (Ca,Na)2[Be(Si,Al)2O6(O,OH,F)], and leucophanite (Ca,Na)2[Be(Si,Al)2O6(O,F)] in that they all contain essential calcium, beryllium, and silicon (Hawthorne and Huminicki 2002). Two chemical analyses gave similar results and one is as follows: SiO2 44.90, Al2O3 2.17, Fe2O3 0.11, MnO 0.07, MgO 0.38, CaO 40.09, BeO 9.49, Na2O 0.72, K2O 0.20, H2O− 0.36, H2O+ 0.90, F 0.25, Cl 0.18, P2O5 0.08, TiO2 trace, -O=(F,Cl)2 0.15, sum 99.94, 99.79% (Fleischer 1963). Common impurities are Ti, Zr, Hf, Al, Fe, Mn, Mg, Na, K, F, Cl, and P (Fleischer 1963).
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