Authenticity Identification of Jinan Qing Marble: 5 Steps for Precise Determination
The authenticity identification of inan Qing (a type of gabbroic granite) centers on appearance texture, density and weight, water absorption rate, tapping sound, and professional testing. Combined with origin and price character this allows for quick identification to avoid being deceived by Zhangqiu Qing, Fujian Qing, dyed stones, or artificial stones.
I. Core Visual Characteristics (Initial Visual Inspetion)
Cuadro
Feature Authentic Jinan Qing Imitation / Fake
Color Gray-black with a bluish tinge; steady base color that is not glaring Pure blck and dull, glossy black (often dyed), or gray-white / light black
Texture Uniform and fine white “sesame spots” / fine cloud patterns; no repetition Large aegular white spots with no pattern, or no white spots
Gloss Natural matte and fine; no artificial coating reflection Too bright and gaudy (dyaxed); fades after wiping with oil
Backside Dark gray / black with natural mineral spots Skinning, glue repair marks, or color too light / too white
Key Tintic texture is natural and unique; each piece is different. Imitation texture is repetitive and dull, often printed or dyed to mimic.
II. Quick Physical Tests (ite Operable)
- Weighing (Most Intuitive)
Authentic: Density 3.0–3.3 g/cm³; noticeably heavier for the same volume; feelsubstantial.
Imitation: Zhangqiu Qing / Fujian Qing density ≤2.8 g/cm³; lighter weight.
Artificial Stone: Even lighter weight; may have internl bubbles. - Tapping Sound (Test for Compactness)
Authentic: Tap lightly with knuckles; sound is crisp and pleasant with a long resonance, indicating no internal crack.
Imitation: Sound is muffled and coarse, often due to internal looseness or hidden cracks. - Water / Ink Drop Test (Test for Water Absorption Rate)
Procedure clear water or ink on a hidden area and let it sit for 5–10 minutes.
Authentic: Water droplet does not spread or seep in; ink ps slowly or not at all (water absorption rate <0.13%). Imitation: Water spreads quickly and leaves a mark; ink seeps in instantly (water absorpion rate >0.3%).
Note: Surface protective coating may temporarily prevent seepage; lightly scrape the surface first before testing. - Scratch Test (Test for Hardnessthentic: Mohs hardness 6–7; no marks when scratched lightly with a steel knife.
Imitation: Low hardness; easily leaves scratches; artificial ston
III. Advanced Professional Testing (Precise Conclusion)
If used for precision components (such as measuring tools, platforms), the following tests arerecommended, and the data can serve as direct evidence:
Density Test: Per GB/T 9966.3, density measured by water displacement mehod; 3.0–3.3 g/cm³ is authentic.
Water Absorption Test: Per GB/T 9966.3; water absorption rate < 0.13% isthentic.
Compressive Strength: ≥257 MPa (2570 kg/cm²); counterfeits are mostly ≤200 MPa.
Mineral Compition: XRF / Microscope testing; Pyroxene 65% , Plagioclase 30% , no large amounts of resin / dye.
ShoreHardness: 70–80 HS, uniform without fluctuation.
IV. Key Points to Avoid Pitfalls (Origin and Price)
Origin: Authentic Jinan Qing is produced exclusiveleng District, Jinan, Shandong; the mine is sealed, and supply is scarce.
Price: Average price of rough blocks is aboutCNY/m³; unit price of precision-processed measuring tools/platforms exceeds 2000 CNY/piece; Zhangqiu Qing / Fujian Qing prices ar only 60%–70% of the authentic product; be wary of low prices.
Common Fakes:
Dyed Stone: Ordinary stone dyed; color fades after wiping with oil a cloth.
Artificial Stone: Resin stone powder; emits black smoke and melts when burned; lacks natural texture.
Laminated Stone: Adhesive paper or glue marks onthe back.
V. Final Determination Process (From Simple to Complex)
Look: Gray-black with a bluish tint uniform sesame spots; no glossy black / pure black.ignificantly heavier than the same volume of other materials.
Tap: Crisp sound, not muffled.
Drop: Non-absorbent / slow absorption.
Test:Density 3.0–3.3 g/cm³, water absorption rate < 0.13%, high pyroxene content.
Verify: Origin certificate and test report; reject low
