Diamonds

In Short

Sir William Crookes presents an authoritative scientific and observational study of the diamond, tracing its journey from deep terrestrial deposits to laboratory synthesis. Drawing on his field trips to the Kimberley mines and rigorous laboratory experiments, Crookes details the geological formations holding the stones, the complex machinery used to extract them, and the chemical dynamics of carbon under extreme heat and pressure. The book endures as a vivid historical snapshot of turn-of-the-century mining engineering paired with pioneering physical chemistry, bridging field natural history, industrial economics, and high-pressure physics into a single narrative of scientific discovery.

The Story

The volume begins with a global survey of diamond deposits, noting occurrences from the alluvial gold washings of California and the peridotite volcanic pipes of Arkansas to the river washings of Brazil and India. Crookes quickly focuses his investigation on South Africa's Cape Colony, the undisputed center of diamond production. He documents his visits to Kimberley in 1896 and 1905, where he was granted unrestricted access to the mines, corporate ledgers, and processing plants by De Beers general manager Gardner F. Williams.

Crookes describes the geological structure of the diamond-bearing locations—vertical volcanic pipes filled with a hydrous silicate rock known as "blue ground" and encased by a surrounding wall of "reef." He details the historical transition of the Kimberley mines from chaotic, dangerous open-pit workings subject to massive, costly reef collapses to sophisticated underground shaft systems. This mechanical evolution forced small claim-holders out, consolidating the industry under the De Beers company, which carefully regulated annual output to match global market demand and maintain prices.

The operational focus shifts to the daily routine of the compounds and processing plants. Crookes surveys the life of native laborers, the heavy security measures, and the deployment of long-sentence convict labor in sorting facilities. He then tracks the mechanical pipeline: blue ground is hoisted from the deep shafts, spread across vast open floors to weather in the sun, or crushed in revolving mills, passed over picking tables, sorted by jigs, and concentrated through the pulsator. At the central diamond office, the stones undergo chemical cleaning in boiling nitric and sulphuric acids before being sorted into ten distinct commercial classes based on size, color, and purity.

Moving from industrial operations to laboratory physics, Crookes turns to the physical properties of carbon. He measures the extreme hardness, high specific gravity, and remarkable optical qualities of the stone. Through polariscopic analysis, he discovers that many diamond crystals exist under severe internal strain due to trapped gas cavities.

The narrative culminates in an inquiry into the genesis of the diamond. Rejecting cosmic meteor theories, Crookes builds upon the experimental work of Henri Moissan and Sir Andrew Noble. He explores how carbon dissolves in molten iron under immense heat and pressure deep within the earth. To prove the point, he details his own successful laboratory attempts to generate microscopic diamond crystals by analyzing the residues of high-explosive cordite detonated inside closed steel vessels, confirming the thermodynamic conditions required for carbon to crystallize into diamond.

How It Unfolds

Surveying the global grounds Crookes surveys diamond deposits across Arkansas, California, Brazil, and India, before anchoring his study in the lucrative volcanic pipes of South Africa's Cape Colony.

Descending into Kimberley The author explores the geology of the Kimberley shafts, examining the blue ground, the surrounding reef walls, and the cataclysmic history of open-pit collapses that forced the mines underground.

Consolidating labor and output The narrative examines the organized compound system, the employment of native and convict workers, and the economic consolidation of small claims into the De Beers corporate monopoly to regulate world prices.

Refining the raw ore Crookes details the mechanical processing of the blue ground, tracing the rock through crushing rollers, revolving picking tables, vibrating jigs, and pulsators until the concentrated gravel yields its gems.

Purifying and sorting at the office In the central diamond office, workers wash thousands of carats in boiling acids, after which expert valuators sort the purified stones into ten distinct categories based on color, clarity, and structural perfection.

Testing physical and optical extremes The investigation turns to laboratory experimentation, testing the stone's extreme hardness under hydraulic pressure, measuring its high refractive index, and observing internal stresses under polarized light.

Synthesizing carbon in the lab Crookes investigates the thermodynamic origin of diamonds, examining cordite explosion residues in closed vessels to demonstrate how iron, intense heat, and pressure crystallize carbon into genuine diamonds.

The People

Sir William Crookes The author and main investigator approaches the subject with meticulous curiosity. He seeks to uncover the exact geological origins and chemical mechanics of diamond formation through direct observation and laboratory testing. His investigation takes him deep into South African mine shafts and into delicate chemical analyses using high-pressure steel cones and boiling acid baths.

Gardner F. Williams The General Manager of the De Beers Consolidated Mines acts as Crookes's host and key practical authority. Williams provides open access to company records, mines, and processing floors. Despite his seventeen years of practical research and vast domain knowledge, he remains skeptical of theoretical formulas regarding diamond crystallization, pointing out that practical data often upends abstract hypotheses.

Captain Dallas The compound superintendent manages native workers and safeguards their accumulated wages. He serves as an observant administrator within the mine's tight security system, maintaining financial accounts for laborers who prefer their physical earnings preserved in original paper wrappings rather than deposited in commercial banks.

The Zulu Claim Supervisor An unnamed native supervisor at Klipdam demonstrates fierce personal fidelity to his original employer. When his master sells an unproductive river washing claim, the supervisor secretly hoards all newly discovered diamonds, presenting them in secret to his former employer to prevent the new owner from benefiting.

In Its Own Voice

"A suitable splinter of diamond will plane curls off a glass plate as a carpenter’s tool will plane shavings off a deal board."

Crookes illustrates the extreme physical hardness of the mineral through direct physical behavior.

"On one of my visits to the diamond office the door opened and in walked two young men, each carrying a large enamelled saucepan containing something steaming hot."

The author captures the unadorned, routine handling of fortunes inside the mine's central processing quarters.

"The diamond is a luxury, and there is only a limited demand for it throughout the world."

Crookes contextualizes the global mining trade within cold economic principles of supply control and price regulation.

What It's Really About

The core of the work lies in demystifying a gemstone long associated with mystery, luxury, and romantic myth. Crookes strips away the folklore to frame the diamond as a pure thermodynamic problem: carbon subjected to extreme physical forces. Underneath the descriptions of South African mining operations lies an inquiry into how high pressure and extreme heat alter fundamental molecular structures. The book explores the relationship between nature's deep-earth processes and human industrial replication, arguing that laboratory science can recreate the exact conditions that formed the earth's natural treasures. It also reveals how industrial engineering and corporate consolidation discipline raw geological chaos into a predictable global commodity.

Why Read It Today

Diamonds offers readers a direct window into early twentieth-century science, written by one of the era's leading experimental chemists. It appeals to readers interested in the history of science, mining technology, geology, and physical chemistry. The narrative balances precise laboratory data—such as specific gravity tables, refractive index comparisons, and thermodynamic calculations—with vivid eyewitness descriptions of industrial operations in turn-of-the-century South Africa.

The text presents some reading hurdles typical of its era. Modern readers will encounter technical terminology regarding mineralogy and chemical extraction, alongside archaic spellings like imbed or peculation. The narrative reflects period colonial attitudes when describing native and convict labor systems in the Kimberley compounds, presenting these setups through the detached lens of industrial efficiency. Nevertheless, Crookes’s prose remains clear, crisp, and accessible. His ability to explain complex physical phenomena—like how diamonds plane glass or reflect light internally—makes the book an engaging historical document that captures the exact moment when natural history transformed into modern high-pressure physics.<ElicitationsGroup message="If you would like to explore this historical work further:">

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