Ramaura Ruby
Ramaura Ruby
A 1980s flux-grown synthetic ruby distinguished by its proprietary dopant signature
Ramaura is the trade name for a flux-grown synthetic ruby produced commercially in the 1980s by the Ramaura Corporation. The material is gemmologically identical to natural ruby in its chemistry — chromium-doped corundum — but its growth environment, inclusion suite, and trace-element signature mark it clearly as synthetic when examined in the laboratory. Ramaura is one of several flux-grown synthetic rubies developed during the period of intense competition in laboratory-grown corundum, alongside Chatham, Kashan, Knischka, Douros, and Ruby J. O. Crystals.
Production method
Ramaura ruby was grown in a high-temperature flux melt — a molten salt or oxide solvent in which alumina dissolves and from which corundum crystallises on cooling — using platinum crucibles and proprietary flux compositions. The process produces facetable crystals over a period of weeks to months, and yields rough that can be cut into faceted stones in a wide range of sizes. The flux growth differs fundamentally from the older Verneuil flame-fusion process: flux-grown synthetics dissolve in a solvent and crystallise out of solution, whereas Verneuil-grown synthetics melt and resolidify by solidification of dropped powder, producing different inclusion patterns and growth structures.
A distinctive feature of Ramaura production was the deliberate addition of a lanthanide-series trace element (commonly identified in the literature as praseodymium or another rare earth) at low levels. The dopant served as a tag detectable by spectroscopy and was included expressly to allow gem laboratories to identify the material as Ramaura synthetic. The decision to include a deliberate identification tag was unusual and represented a more co-operative attitude toward laboratory identification than is typical of synthetic-stone producers.
Identification
Ramaura ruby shows several diagnostic features. Inclusion patterns characteristic of flux growth include wispy veils, fingerprint inclusions, and platinum platelets — small triangular or hexagonal silvery flakes from the platinum crucible — which are absent in natural ruby and in flame-fusion synthetics. Strong red short-wave ultraviolet fluorescence, typically more vivid and uniform than natural ruby, is another routine indicator. The proprietary lanthanide dopant produces small but characteristic features in ultraviolet-visible spectra.
For laboratory examination, the combination of magnification (which reveals the platinum particles and flux veils), ultraviolet response, and absorption spectra is normally sufficient for confident identification. Energy-dispersive X-ray fluorescence and Raman spectroscopy provide additional confirmation where required. The material does not present the identification difficulty of more recent hydrothermally grown synthetics.
Market history
Ramaura entered the market in the early 1980s and was actively traded for roughly a decade. Production has ceased and the company is no longer in operation, but Ramaura material remains present in older jewellery and turns up periodically at gem shows and on the secondary market. Identification by a laboratory is straightforward, and the material is unambiguously synthetic and disclosed as such on reputable trade documents.
Ramaura ruby was one of several entrants in the period when synthetic ruby production diversified beyond the Verneuil process. Chatham, Kashan, Knischka, and Ramaura each occupied positions in the market, with their inclusion patterns and trace-element profiles documented in the gemmological literature of the 1980s and 1990s. Hydrothermal synthetic ruby, produced more recently, presents a different identification challenge and has largely supplanted flux-grown material in the contemporary synthetic-corundum trade.
In the trade
Ramaura ruby is encountered today primarily in older inventory, estate jewellery, and the secondary market. Trade rules under AGTA and CIBJO require disclosure of synthetic origin on invoices and reports, and any responsible dealer offering Ramaura material identifies it explicitly as synthetic. Pricing reflects synthetic-ruby economics rather than natural-ruby economics; the material trades at a small fraction of the price of equivalent natural ruby of comparable colour and clarity.
Care
Ramaura ruby is corundum at 9 on the Mohs scale and behaves as natural ruby for cleaning and setting purposes. Ultrasonic and steam cleaning are generally safe; standard prong, bezel, and channel settings are appropriate. Heat treatment, the routine treatment of natural ruby, is not relevant for Ramaura material because the colour is established at growth and does not require subsequent enhancement.