Gem Instrument / Gemological Instrument 

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XHST2551 Optical Spectroscope


The type XHST2551 spectroscope is one of physical experimental instrument in a middle school. It may be used to illustrate construction of the spectroscope, observe continuous spectrum, bright line and absorption spectra, and measure the wavelength of spectral line and Planck constant, etc.

1. Working wavelength: 400-800nm
2. Objective focal length of collimator: 150mm
3. Objective focal length of telescope: 150mm
    Eyepiece focal length of telescope: 25mm (low power)
                                                       12.5mm (high power)
4. Objective focal length of drum calibrated in wavelength: 100mm
5. Minimum graduation of wavelength scale: 2nm per graduation for 400-500nm
                                                                5nm per graduation for 500-600nm
                                                                10nm per graduation for 600-700nm
                                                                20nm per graduation for 700-900nm
6. Prism: refracted edge angle of 60<
7. Error in measuring wavelength: not greater than 2nm for 400-500nm
                                                 not greater than 5nm for 500-600nm
                                                 not greater than 10nm for 600-700nm
                                                 not greater than 20nm for 700-800nm
8. Resolving power: resolving mercury doublet 577nm and 579nm in using eyepiece at low magnifying power, resolving sodium doublet 589nm and 589.6nm in using eyepiece at high magnifying power.
9. Dispersion: at focal plane of the telescope, the distance between two spectral lines 656.3nm and w34nm of hydrogen atom is not less than 9mm, average line dispersive power is not greater than 24.7nm/mm.

XHST1018-PS Professional loupe
Professional Loupe for gemstones identifying. To see the internal or surface characteristics of gemstone.
10X loupe chromatism
18mm lens

Diamond Tester Scale DMT-300

Diamond Tester Scale DMT-500

Model: DMT-300  (Economic)

Product introduction:

1. Real Diamonds are indicated by RED LIGHT and SOUND.
2. Card size and compact
3. High accuracy, User-friendly
4. Can work with stones of any settings, shapes,
5. Can work with stones of any sizes in any temperature.
6. Dimensions (L x W x H): 85mmx54mmx 14mm
7. Power Supply:2 x AAA battery
8. Weight .75g .
9. 150pcs/carton Carton Size (L x W x H): 65cmx30cmx 15cm

Model: DMT-500  (Economic)

Product introduction:

- Simple one step testing that will distinguish between diamonds, simulate, and moissanite
- 3 audible sounds to give a warning buzzer Easy to use visual and audio indicators Fast warm up and recovery time Operates on one 9 voltage battery (not included) Auto shuts off automatically after three minutes to save the battery Completely portable Weight: 80g


Diamond Tester Scale DMT-400

Model: DMT-400  (Economic)

Product introduction:

1.Secification: Diamond Tester.
2.Working Voltage: DC 9v,6F 22 battery or AC adaptor(AC110-240 V, DC   9V,optional accessories)
3.Probe warming up time: about 25 seconds.
4.Working time: About 5 hours for continuous use
5.Ambient temperature:18C to 30C


GEM Calper DC-3


Made of Lightweight Non-Marring Carbon Fiber Material. Free of hurting when measuring.
It is suited for measuring jewelry, magnetic objects and charged objects.
1.ON/OFF Switch Switch
3.Zero setting
4.Runs on by one 1.5V cell battery

Item No.


Throat depth







For other Gem gauges, please check here: Gem Thickness Gauge


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 ( If you need user manual or E-catalogue for above meters, please ask for at: )