The Hixon Ruby Crystal
The Hixon Ruby Crystal
A 196.10-gram gem corundum specimen at the Natural History Museum of Los Angeles County
The Hixon Ruby Crystal is one of the most significant uncut ruby specimens held in an American museum collection, weighing 196.10 grams and distinguished by its well-developed hexagonal crystal habit. Displayed in the Gem and Mineral Hall of the Natural History Museum of Los Angeles County (NHMLAC), the specimen represents ruby — the red gem variety of the mineral corundum (aluminium oxide, Al₂O₃) — in its natural, unmodified state, offering visitors and researchers a rare opportunity to study the morphology of a large gem-quality corundum crystal outside the cutting laboratory. Its combination of size, crystallographic integrity, and chromium-rich red colouration places it among the foremost ruby display specimens in North America.
The Specimen: Physical and Mineralogical Character
Ruby belongs to the trigonal crystal system, and its characteristic growth form is the hexagonal prism, often terminated by rhombohedral or basal pinacoidal faces. The Hixon crystal exemplifies this habit with clarity: its prismatic faces are well-defined, and the overall geometry communicates, even to a non-specialist observer, the ordered internal symmetry of the corundum lattice. At 196.10 grams — equivalent to 980.5 carats — the specimen is substantially larger than the vast majority of ruby crystals that reach the gem trade, where stones of even a few carats of fine colour command exceptional prices and crystals of several hundred carats in gem-quality material are genuinely rare.
The red colouration of ruby is caused by the substitution of a small proportion of aluminium ions by chromium (Cr³⁺) within the corundum structure. Chromium absorbs light in the yellow-green region of the visible spectrum and transmits red, producing the characteristic hue. In fine specimens, a secondary fluorescence effect — also driven by chromium — causes the stone to re-emit absorbed ultraviolet and visible light as red luminescence, intensifying the apparent colour under daylight and fluorescent illumination. Whether the Hixon crystal displays this fluorescence to a marked degree is consistent with its chromium content, as virtually all natural rubies fluoresce to some extent under long-wave ultraviolet light.
The specimen is presented in the rough, meaning it has not been shaped, faceted, or polished beyond any cleaning or minimal conservation treatment. This is a deliberate and scientifically valuable choice: an uncut crystal preserves the original surface features — growth striations, etch figures, natural terminations, and any inclusions visible at or near the surface — that are erased by the lapidary's wheel. For gemmological education, such a specimen is irreplaceable as a physical reference for the natural morphology of corundum.
Provenance and the Hixon Gift
The crystal takes its name from the Hixon family, whose philanthropic gifts to the Natural History Museum of Los Angeles County significantly enriched the institution's gem and mineral holdings during the latter half of the twentieth century. Frank D. Hixon and his family were among the notable benefactors whose donations of both specimens and endowment funds helped establish the NHMLAC Gem and Mineral Hall as one of the premier public displays of its kind on the American West Coast. The naming of the ruby crystal in their honour follows a long tradition in natural history museums of recognising major donors through the association of their names with outstanding specimens.
The precise geographic origin of the Hixon Ruby Crystal — the mine or region from which it was extracted — does not appear to be definitively recorded in widely available published sources, and it would be imprudent to assign a locality without documentary confirmation. The world's most historically celebrated ruby localities include Mogok in Myanmar (Burma), Mong Hsu in Myanmar, Luc Yen and Quy Chau in Vietnam, Montepuez in Mozambique, and various deposits in Thailand, Madagascar, and Afghanistan. Large, well-formed crystals of the type represented by the Hixon specimen have historically been associated with marble-hosted deposits such as those at Mogok, where the relatively slow crystallisation environment within metamorphic limestone can permit the growth of sizeable, well-terminated prisms. However, without a confirmed locality record, any such attribution for this specific crystal remains speculative.
Significance in Context: Large Ruby Crystals and Their Rarity
To appreciate the Hixon Ruby Crystal properly, it is worth situating it within the broader landscape of large ruby specimens. Corundum itself is not an uncommon mineral — sapphire and ruby occur on every inhabited continent — but the convergence of factors required to produce a large crystal of gem quality is statistically improbable. The crystal must grow slowly enough to develop good form, in a chemical environment sufficiently rich in chromium to produce saturated red colour, without the inclusions, fractures, or colour zoning that would disqualify it from gem consideration, and it must then survive extraction, transport, and the commercial pressures that incentivise cutting.
The commercial incentive to cut is powerful. A 196-gram ruby crystal, if it contained even a modest proportion of facetable gem-quality material, would represent an extraordinary financial asset in the cut-stone market, where fine rubies of Burmese origin routinely achieve prices exceeding tens of thousands of US dollars per carat at major auction houses. The decision to preserve a specimen of this scale uncut — whether made by a private collector, a dealer, or an institution — reflects a judgement that its scientific and educational value in the rough exceeds its value as a source of cut stones. Museums have historically been the custodians of such judgements, and the Hixon crystal's presence at the NHMLAC is a direct expression of that institutional mission.
Comparable large ruby crystals held in museum collections worldwide include specimens at the Smithsonian Institution's National Museum of Natural History in Washington, D.C., the American Museum of Natural History in New York, and the Natural History Museum in London. Each of these institutions holds uncut or minimally worked corundum specimens that serve analogous educational functions. The Hixon crystal is distinguished within this company by its weight and by the quality of its crystal form.
Gemmological and Educational Value
Museum-quality rough specimens such as the Hixon Ruby Crystal fulfil several functions that cut stones cannot. First, they demonstrate the natural growth geometry of the mineral, making abstract crystallographic concepts tangible for students and the general public. The hexagonal cross-section of a ruby prism, visible in a well-formed crystal, directly illustrates the trigonal symmetry of the corundum structure in a way that a faceted oval or cushion-cut stone does not.
Second, rough specimens preserve the surface record of the crystal's growth history. Striations parallel to the basal plane, characteristic of corundum, are visible on prismatic faces and reflect the layer-by-layer growth of the crystal. Etch figures — dissolution features produced when a crystal is partially resorbed by the surrounding melt or fluid — can indicate the thermal history of the deposit. These features are studied by gemmologists and mineralogists to understand the conditions under which gem corundum forms.
Third, large reference specimens provide a physical standard against which the properties of smaller stones can be calibrated. Colour, diaphaneity, and the character of natural inclusions can all be observed and compared in a large, well-lit museum specimen in ways that are difficult to replicate with small, mounted stones.
For the general public, the Hixon Ruby Crystal serves the additional function of communicating the natural origin of gemstones — a message of increasing importance as synthetic and simulant stones become ever more sophisticated and as consumers become progressively more distant from the geological processes that produce the materials they wear. A 196-gram ruby crystal, displayed in its natural state under museum lighting, is an unambiguous statement about the earth's capacity to produce objects of extraordinary beauty without human intervention.
The Natural History Museum of Los Angeles County
The Natural History Museum of Los Angeles County, founded in 1913, is the largest natural and historical museum in the western United States. Its Gem and Mineral Hall houses one of the most extensive public displays of gem and mineral specimens on the West Coast, encompassing faceted gemstones, rough crystals, and mineral suites representing the full breadth of the earth's mineralogical diversity. The Hall has been a significant destination for gemmological education in Southern California, and its holdings — built through a combination of institutional acquisition and private philanthropy — include specimens of international importance across multiple mineral families. The Hixon Ruby Crystal is among the most prominent of the Hall's gem corundum holdings and is typically among the specimens highlighted in the museum's educational programming.
In the Trade and Among Collectors
The existence of the Hixon Ruby Crystal is of interest to the gem trade not only as a specimen of record but as a reminder of what the rough ruby market occasionally produces. Dealers and collectors who specialise in mineral specimens — a market distinct from, though overlapping with, the gem trade — actively seek large, well-formed ruby crystals, and prices for exceptional examples at mineral shows and specialist auctions can be substantial. The decision to donate or sell such a specimen to a museum rather than to a private collector or cutting house reflects a set of values — scientific preservation, public access, educational mission — that the gem trade increasingly recognises and respects, even when the commercial alternative would be financially superior.
The Hixon Ruby Crystal, in this sense, is not merely a geological curiosity or a philanthropic monument. It is a working scientific instrument, a public artwork, and a permanent record of what the earth's crust, under the right conditions of temperature, pressure, and chemistry, is capable of producing. Its continued display at the Natural History Museum of Los Angeles County ensures that these functions endure for future generations of students, gemmologists, and admirers of the natural world.