Fable FUV-4 Professional Gemological UV Lamp with Darkroom – Longwave & Shortwave

⭐ RIDDGEM Checked & Tested – Shipped from Sweden – no import fees within the EU ⭐

Complete professional UV fluorescence instrument featuring both longwave UV-A (365 nm) and shortwave UV-C (253.7 nm), an integrated observation darkroom and magnifying viewing eyepiece. A highly useful gemological tool for the examination and identification of diamonds and gemstones.

Fluorescence is an important diagnostic property of many gemstones and minerals. When exposed to ultraviolet radiation, certain substances within a material may absorb UV energy and emit visible light – causing the gemstone to fluoresce.

The Fable FUV-4 provides two important UV wavelengths traditionally used in gemology:

• LW – Longwave UV-A, 365 nm
  Commonly used to observe fluorescence in diamonds, rubies and many other gemstones and minerals.
• SW – Shortwave UV-C, 253.7 nm
  Provides additional diagnostic information, as a gemstone may react very differently under shortwave UV compared with longwave UV.
• By comparing a gemstone's reaction under LW and SW illumination, the gemologist can obtain valuable diagnostic information when examining natural, synthetic and imitation materials.
• UV fluorescence should, however, be used in combination with other gemological tests and is normally not sufficient on its own for definitive identification.

Integrated Observation Darkroom

• Unlike the simpler FUV-4B, the FUV-4 is a complete observation instrument with an integrated darkroom.
• The gemstone is conveniently placed inside the pull-out observation drawer. The enclosed design reduces interference from ambient light and creates a dark environment where even weaker fluorescence can be easier to observe.
• A magnifying viewing eyepiece allows the fluorescence of the gemstone to be examined closely while helping prevent direct viewing of the UV light source.
• This makes the FUV-4 considerably more convenient for regular gemological work than a separate UV lamp that requires a darkened room.

Fascinating for Collectors Too

UV fluorescence is not only useful in a gemological laboratory – it is also a fascinating way to explore a personal collection of gemstones and minerals.

Many natural rubies, for example, may display intense red fluorescence under longwave UV light, while some diamonds show clearly visible fluorescence, often blue.

The reaction varies depending on the chemical composition and other properties of the gemstone, and some specimens may show weak or no fluorescence at all.

Specifications

Model: Fable FUV-4
UV light: Dual wavelength
LW / Longwave: 365 nm (UV-A)
SW / Shortwave: 253.7 nm (UV-C)
Observation darkroom: Yes, integrated pull-out observation drawer
Viewing: Magnifying observation eyepiece
Dimensions: Approx. 170 × 170 × 140 mm
Weight: Approx. 2.0 kg
Power supply: External 12 V / 1 A
Adapter: EU adapter included

FUV-4 – Complete UV Observation System

The Fable FUV-4 combines the UV light source and observation darkroom in one compact instrument.

Simply place the gemstone inside the drawer, close it and select either LW 365 nm or SW 253.7 nm. The fluorescence can then be examined through the observation eyepiece while the enclosed darkroom reduces interference from surrounding light.

For larger gemstones or mineral specimens that do not fit inside the observation chamber, the UV lamp section can also be used separately. The specimen should then be examined in a darkened room.

Important Safety Information

• Never look directly into the UV light source.
• Avoid exposing skin and hands to shortwave UV-C radiation.
• Do not insert or remove gemstones while the UV lamp is switched on.
• Switch off the UV light before opening the observation drawer.
• Always switch off the instrument after completing the examination.

Shortwave UV-C vs Longwave UV-A

A gemstone does not necessarily react in the same way under both wavelengths. It may fluoresce strongly under LW and weakly under SW – or vice versa. Comparing these reactions can provide the gemologist with additional diagnostic information.

• LW 365 nm is longwave UV-A and is commonly used as an initial fluorescence test.
• SW 253.7 nm is shortwave UV-C and may produce different reactions that complement observations made under LW illumination.
• The combination of LW + SW ultraviolet light and an integrated observation darkroom makes the Fable FUV-4 a complete and highly useful fluorescence examination instrument for the gemological laboratory.