⏳ Made to order - picked up after purchase - delivery time approximately 2-4 weeks and no open purchase⏳

Fable FUV-4Z Professional Gemological UV Lamp with Diamond Roller – LW 365 nm / SW 253.7 nm

Advanced professional UV instrument for gemological examination of diamonds and gemstones. The FUV-4Z combines longwave UV-A 365 nm and shortwave UV-C 253.7 nm with an integrated observation darkroom, magnifying eyepiece and Fable's unique Diamond Roller for efficient examination and comparison of diamonds.

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

The Fable FUV-4Z provides two important UV wavelengths 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 the same gemstone may react very differently under shortwave and longwave UV illumination.
• By comparing a gemstone's reaction under LW and SW illumination, the gemologist can obtain valuable supplementary information when examining natural, synthetic and imitation materials.
• UV fluorescence should, however, be regarded as a complementary gemological test and used together with other examination methods.

Diamond Roller – Designed for Diamond Examination

The main feature distinguishing the FUV-4Z from the FUV-4 is the integrated Diamond Roller device.

The system facilitates positioning, movement and comparison of diamonds during examination. It provides observation from both the table and pavilion sides and allows the tested diamond to be conveniently moved outside the darkroom for comparison and further assessment.

This makes the FUV-4Z particularly suitable for gemologists, diamond dealers, jewellers and laboratories regularly examining and comparing multiple diamonds.

Integrated Observation Darkroom

• The FUV-4Z incorporates a darkroom with a convenient pull-out observation drawer.
• The gemstone is placed inside the observation area and the drawer is closed to reduce interference from ambient light. This creates a controlled dark environment in which even weaker fluorescence can be easier to observe.
• A magnifying viewing eyepiece allows fluorescence to be examined closely without looking directly towards the UV light source.

LW + SW – Two Wavelengths Provide More Information

A gemstone does not necessarily react in the same way under both UV wavelengths.

A stone may, for example, display strong fluorescence under LW illumination but weak or no fluorescence under SW – or vice versa.

LW 365 nm is commonly used as an initial fluorescence examination.

SW 253.7 nm may produce different reactions and therefore provide additional diagnostic information.

The combination of both wavelengths makes the FUV-4Z considerably more versatile for professional gemological work than simpler UV lamps providing only a single wavelength.

Specifications

Model: Fable FUV-4Z
UV light: Dual wavelength
LW / Longwave: 365 nm (UV-A)
SW / Shortwave: 253.7 nm (UV-C)
Observation darkroom: Yes, integrated
Observation drawer: Pull-out design
Viewing: Magnifying observation eyepiece
Diamond Roller: Yes
Diamond observation: Table and pavilion sides
Power supply: External 12 V / 1 A
Dimensions: Approx. 170 × 170 × 140 mm
Weight: Approx. 2.2 kg

FUV-4Z – The Advanced Model

The FUV-4Z builds on the functionality of the FUV-4 and adds the Diamond Roller for more efficient handling, observation and comparison of diamonds.

This makes the model particularly suitable for professional users who regularly work with diamond examination.

FUV-4B – LW + SW, stand-alone UV lamp
FUV-4 – LW + SW + integrated observation darkroom
FUV-4Z – LW + SW + observation darkroom + Diamond Roller

For general professional gemological use, RIDDGEM recommends the FUV-4 as a highly complete instrument. For users working more specifically and regularly with diamonds, the FUV-4Z provides additional functionality through its Diamond Roller system.

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.
• When examining very large specimens outside the darkroom, use the lamp in a darkened room.
• Always switch off the instrument after completing the examination.