“[Mister] Renous, alluding to myself, asked him what he thought of the King of England sending out a collector to their country, to pick up lizards and beetles, and to break stones? The old gentlemen thought seriously for some time, and then said, "... no man is so rich as to send out people to pick up such rubbish." - Journal and remarks, 1832-1836, by Charles Darwin.
Charles Robert Darwin was born on February 12, 1809, in Shrewsbury, county town of Shropshire, and from an early age on loved to collect things. He noted this in his autobiography. "It was soon after I began collecting stones, i.e., when 9 or 10, that I distinctly recollect the desire I had of being able to know something about every pebble in front of the hall door–it was my earliest and only geological aspiration at that time."
During his school years, Darwin remains interested in chemistry and minerals, however, he laments that "I continued to collecting minerals with much zeal, but quite unscientifically – all that I cared was a new named mineral, and I hardly attempted to classify them."
As a student of medicine at Edinburgh University, Darwin frequented various courses on natural sciences, including lectures by mineralogist Robert Jameson. "During my second year at Edinburgh I attended Jameson's lectures on Geology and Zoology, but they were incredibly dull. The sole effect they produced on me was the determination never as long as I lived to read a book on Geology, or in any way to study the science."
Despite Darwin's criticism of Jameson's public lectures, it's clear he regularly used Jameson's Manual of Mineralogy for his private studies, as it is one of the most heavily annotated books found in his library. He remembers in his autobiography, "...an old Mr. Cotton, in Shropshire, who knew a good deal about rocks, had pointed out to me ... a well-known large erratic boulder in the town of Shrewsbury, called the 'bell-stone;' ... This produced a deep impression on me, and I meditated over this wonderful stone."
At the time, mineralogy manuals used physical properties, such as color, crystal shape and degree of hardness for mineral and rock identification. German geologists pioneered the identification of minerals. Carl Friedrich Christian Mohs published one of the first modern textbooks on mineral classification and identification in 1824.
In his later career as geologist, Darwin would describe rocks based on their visible properties. For example, he used terms like "porphyry" for rocks with large, well visible, crystals, or he used names like “greystone” or “greenstone” to describe greenish-dark magmatic rocks, today classified as a dolerite-basalt (and to confuse modern geologists, greenstone is nowadays the name used for a metamorphic rock). He also used many terms introduced by German geologists, like "amygdaloid," which describes cavities filled with crystals found in basaltic lava flows.
Darwin's interest in nature led him to neglect his medical education at the University of Edinburgh. His disappointed father, a physician himself, sent him to Christ's College, Cambridge, to study for a Bachelor of Arts degree as the first step towards becoming an Anglican country parson. At Cambridge, Darwin met William Whewell, an amateur mineralogist himself, and befriended one of the top geologists of the day, Adam Sedgwick, president of the newly formed Geological Society of London. He visited the private lectures on geology and botany by Sedgwick and John Stevens Henslow botanist and geologist. Sedgwick took the young Darwin on a geological field trip to Wales in summer of 1831.
Darwin was interested in acquiring the basics of geological fieldwork, structural geology and rock classification. Twenty pages of notes made by Darwin during this tour are still preserved today. In his autobiography, he would later remember, "This tour was of decided use in teaching me a little how to make out the geology of a country."
When Darwin returned back home, a letter from Captain Robert FitzRoy was waiting for him. It offered him a position as gentlemen companion on board of the H.M.S. Beagle, ready to set sail from Plymouth at the end of the year. FitzRoy was himself an amateur geologist and delighted to get a "young man of promising ability, extremely fond of geology” as companion during the long voyage of the Beagle around the world. Darwin used the remaining time to exercise mineral identification and proudly remarks "hornblende determined by myself."
On board the Beagle, Darwin had access to a complete library for mineral identification, including A selection of the Geological Memoirs (1824), featuring a mineral identification chart compiled by famous French geologist Alexandre Brongniart. These manuals used, like modern books, properties like color, hardness and shape to identify crystals and minerals and, unlike modern textbooks, also taste and odor.
Especially interesting were classification charts based on the color of a sample. Werner's nomenclature of colors published in 1821 by Patrick Syme is a book displaying just a chart and the description of various colors to be compared with minerals, animals and plants. Darwin himself brought this book on board of the Beagle and used it to describe snakes, rocks and even the "beryl blue" glaciers visited in South America.
During the five-year-long voyage of the Beagle, Darwin compiled 1.383 pages of notes about geology. By comparison, the biological observations that made him famous comprised a mere 368 pages. In April 1832, the Beagle arrived at Rio de Janeiro, Brazil with a seasick Charles Darwin. On land, Darwin received news from home, including a letter by Fanny Owen, a woman he hoped was waiting for him back home. She had married someone else.
Perhaps to lift his spirits, Darwin decided to geologize a bit around the city, climbing the Pão de Açúcar (Sugarloaf Mountain). Darwin described in detail the rock and collected various samples of "gneiss, abounding with garnets, and porphyritic with large crystals, even three and four inches in length, of orthoclase feldspar: in these crystals, mica and garnets are often enclosed."
Darwin's final advice for collecting rocks and minerals is still important today: "Put a number on every specimen, and every fragment of a specimen; and during the very same minute let it be entered in the catalogue, so that if hereafter its locality be doubted, the collector may say in good truth, 'Every specimen of mine was ticketed on the spot.' Any thing which is folded up in paper, or put into a separate box, ought to have a number on the outside (with the exception perhaps of geological specimens), but more especially a duplicate number on the inside attached to the specimen itself."
