How to tell if a crystal is natural or cultured?

Observe the internal features

• Inclusions:
  • Natural crystals: They usually have various naturally formed inclusions inside. For example, there are irregularly distributed gas-liquid two-phase inclusions, which look like tiny bubbles or cloud-like substances, with a very natural and random appearance. There may also be mineral inclusions, such as hair-like or needle-like inclusions formed by rutile, tourmaline, etc., and the arrangement and direction of these inclusions are usually disordered. For instance, in natural rutilated quartz, the thickness, length and direction of the “hairs” inside are not uniform.
  • Synthetic crystals: The interior is relatively clean and pure. Even if there are inclusions, they are mostly regular and evenly distributed, like the traces left during the manufacturing process or the substances added deliberately to mimic inclusions, which look rather artificial and unnatural. For some synthetic crystals that imitate the natural effect by adding hair-like inclusions, the “hairs” are often of uniform thickness and neatly arranged.
• Growth textures:
  • Natural crystals: Affected by the environment during the growth process, the crystal surface may have growth textures such as horizontal and vertical stripes. These textures are naturally formed, with natural bends, interruptions and other situations, and the texture characteristics may vary in different parts. For example, when observing a natural clear quartz crystal column from the side, irregular growth lines can be seen.
  • Synthetic crystals: The growth textures are generally more regular, and may present relatively neat and uniform patterns, because they grow in a relatively stable and controllable artificial environment. For example, some show concentric ring-shaped textures, and the intervals between the rings are relatively even.

Test physical properties

• Hardness test:
  • Natural crystals: They have a hardness of about 7 on the Mohs scale. When using them to scratch items with a hardness lower than 7, such as feldspar (with a hardness of about 6 – 6.5), scratches can be left on the surface of the feldspar while the crystal itself is basically not damaged. However, this testing method should be used with caution to avoid damaging the crystal itself.
  • Synthetic crystals: Although theoretically the hardness is close to that of natural crystals, due to possible slight differences in the internal structure and other aspects, the actual hardness performance of some synthetic crystals may be slightly weaker. When conducting the hardness test, they may be more likely to have abrasions and scratches than natural crystals, but this requires careful comparison to notice.
• Density comparison:
  • Natural crystals: The density is relatively fixed, usually around 2.65 grams per cubic centimeter. By accurately measuring its density with professional density measuring instruments and then comparing it with the standard value, those that match are likely to be natural crystals. However, this kind of measurement is rather difficult for ordinary consumers to operate and usually requires the assistance of professional laboratory equipment.
  • Synthetic crystals: Their density may deviate from that of natural crystals due to factors such as the cultivation process and added components. The density of some synthetic crystals may be slightly lower, but the difference is often small and can only be distinguished by precise measurement.

Check the price and source

• Price:
  • Natural crystals: Especially those with good quality, large crystals, beautiful colors and special optical effects (such as starlight effect, cat’s eye effect), usually have relatively high prices. For example, high-quality natural amethyst geodes can range in price from several hundred yuan to several thousand yuan or even higher depending on factors such as size and color. And some rare natural crystal varieties are even more expensive. If you encounter a so-called “natural crystal” with a significantly low price, it is most likely a synthetic crystal or a fake.
  • Synthetic crystals: Since they can be produced in large quantities under artificial control and have relatively low costs, the prices are generally relatively cheap. They are often used to make some affordable jewelry and ornaments. For example, an ordinary synthetic crystal bracelet can be bought for about ten to several tens of yuan.
• Source channels:
  • Natural crystals: They are generally obtained through natural means such as mining. Formal sales of natural crystals will have corresponding certificates of origin, appraisal certificates, etc. (for example, natural crystals from Brazil will have relevant vouchers from the origin). If the source channel is relatively formal and can be traced back to the natural mining source, it is more likely to be a natural crystal.
  • Synthetic crystals: They mostly come from artificial cultivation factories. Some of the products sold will also clearly indicate that they are synthetic crystals. If the merchant is ambiguous and unable to clarify the source situation, you should be cautious in judgment.

Seek professional appraisal

• Appraisal by professional institutions:
  • You can send the crystal to a professional gemstone appraisal institution, such as the National Gemstone Quality Supervision and Inspection Center. These institutions will use professional instruments and equipment, such as observing the optical properties of the crystal through a polarizing microscope and analyzing its composition with an infrared spectrometer, to accurately identify whether the crystal is natural or synthetic and issue an authoritative appraisal certificate.
• Check the appraisal certificate:
  • ICIA’s appraisal certificate will clearly list the type of crystal, whether it is natural and other related properties. If the certificate has a qualification certification mark, an appraisal agency seal and a searchable serial number, the authenticity of the certificate can be checked through ICIA’s official channels (such as the agency’s official website) to confirm the nature of the crystal.

It should be noted that it may be difficult to accurately judge by relying on only one method alone. It is best to use multiple methods comprehensively for identification.