Six months ended June 30, 2020 compared to the six months ended June 30, 2019
Revenues
Revenues decreased $27.8 million, or 4.9%, for the six months ended June 30, 2020, as compared to the six months ended June 30, 2019, primarily as a result of a significant decline in our GMF segment revenues. EL segment revenues increased by $42.8 million to $357.8 million, or 13.6%, for the six months ended June 30, 2020, as compared to the six months ended June 30, 2019, while GMF segment revenue was $185.8 million, a decline of $70.6 million, or 27.5%, over the same period. Chemistry revenues decreased by $6.2 million, or 1.2%, to $499.5 million for the six months ended June 30, 2020, as compared to the six months ended June 30, 2019, while equipment revenues of $44.1 million declined by $21.6 million, or 32.9%. Chemistry revenues for the six months ended June 30, 2020 were positively impacted by fluctuations in palladium prices, which increased revenues by $40.3 million, as compared to the six months ended June 30, 2019, and were also impacted by an unfavorable exchange rate translation, reducing revenues by $11.9 million. Excluding the impact of these items, our chemistry revenues decreased by $34.6 million, or 6.8%, for the six months ended June 30, 2020, as compared to the six months ended June 30, 2019, driven largely by the softened GMF chemistry and equipment markets, partially offset by the growth in our EL segment. For additional information on the key factors driving the changes in our chemistry revenues within our segments, see “—Selected Segment Information.”
Cost of sales
Cost of sales increased $10.2 million, or 4.4%, to $241.4 million for the six months ended June 30, 2020, as compared to the six months ended June 30, 2019, primarily reflecting increased palladium prices. Cost of sales as a percentage of revenues increased from 40.5% to 44.4% for the six months ended June 30, 2020, as compared to the six months ended June 30, 2019.
Depreciation and amortization
Depreciation and amortization increased $276.8 million, or 330.4%, to $360.6 million for the six months ended June 30, 2020, as compared to the six months ended June 30, 2019. This increase was primarily caused by a $279.5 million goodwill impairment in our GMF segment.
Selling, general, and administrative expenses
Selling, general, and administrative expenses decreased $11.6 million, or 8.4%, to $126.9 million for the six months ended June 30, 2020 as compared, to the six months ended June 30, 2019. This decrease is primarily attributable to decreased selling expenses in the amount of $11.1 million primarily due to our additional cost saving measures implemented during the COVID-19 pandemic.
Research and development expenses
R&D expenses decreased $4.3 million, or 15.3%, to $23.6 million for the six months ended June 30, 2020, as compared to the six months ended June 30, 2019. This decrease is primarily attributable to process efficiencies and cost savings measures.
Restructuring benefit (expenses)
Restructuring benefit was $0.3 million for the six months ended June 30, 2019, as compared to a restructuring expense of $1.7 million the six months ended June 30, 2020. This change mainly relates to the severance payments made in Germany.
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