Undisclosed thermal treatments, synthetic overgrowth, and misattributed maker marks carry real financial risk. Every specimen and decorative object cataloged by House of Design Research undergoes non-destructive optical, gravimetric, and metallurgical verification prior to trade release.
Custom diffraction-grating optical imaging calibrated against known mercury-phosphor emission peaks and processed via multi-channel ImageJ spectral extraction.
Determination of refractive index (RI), birefringence, and optic sign paired with digital slit-spectroscopy to isolate chromophore absorption bands (Cr³⁺, Fe²⁺/Fe³⁺, Co²⁺, and rare-earth signatures) and separate natural stones from synthetic or glass simulants.
Precision specific gravity (SG) measurement via suspended hydrostatic weighing in distilled media, followed by darkfield and oblique fiber-optic stereo microscopy to document crystal growth zoning, fluid/mineral inclusions, and heat-treatment indicators.
Precious metal mountings undergo inductive eddy-current conductivity profiling and galvanic electrochemical comparison against pure copper reference standards—avoiding acid-scratch damage on period platinum, gold, and silver work.
| Instrument / System | Measurement Parameter | Primary Application |
|---|---|---|
| Diffraction Spectroscope & CMOS Rig | λ 400–700 nm Absorption | Chromophore identification in corundum, beryl, spinel, garnet, and cobalt/uranium studio glass. |
| Critical-Angle Gemological Refractometer | n = 1.300 – 1.810 (±0.002) | Single/double refraction separation, birefringence calculation, and optic character determination. |
| Hydrostatic Specific Gravity Balance | SG (g/cm³) Archimedes | Non-invasive bulk density verification for mounted and unmounted rough or faceted specimens. |
| Stereo Darkfield & Polarizing Microscope | 10x–60x + Crossed Polars | Inclusion mapping, silk/rutile integrity checks (unheated vs. thermally altered), and strain patterns. |
| Filtered 365 nm Longwave UV Source | LWUV Excitation Response | Fluorescence zoning in diamonds, Burmese vs. Thai ruby screening, and uranium/manganese glass attribution. |
| Inductive Eddy-Current & Galvanic Suite | Relative Alloy Conductivity | Non-destructive differentiation of high-karat gold, platinum-group alloys, sterling silver, and base-metal cores. |
In-house hardware modifications and non-destructive testing protocols developed to resolve real-world attribution challenges.
By integrating an Optex 80B optical attenuation filter onto the primary 3000K halogen light source, mid-spectrum intensity was flattened to allow higher sensor exposure without clipping. This expanded reliable spectral capture from 445–715 nm down into the 390–750 nm range—critical for isolating UV-blue edge absorption features that separate natural stones from synthetic counterparts.
Constructed a custom audio-frequency inductive field rig utilizing salvaged transformer cores to measure eddy-current voltage drop across unknown metal mountings. Unlike surface acid testing, the magnetic field penetrates below heavy plating or vermeil to differentiate solid sterling silver, low-karat gold, and plated base-metal cores without marring period pieces.
Browse verified holdings in the visual archive or access wholesale trade specifications.